Power supply detection circuit and robot

Abstract

A power supply detection circuit and a robot, comprising a first unidirectional conducting element, a second unidirectional conducting element, a third unidirectional conducting element, a fourth unidirectional conducting element, a fifth unidirectional conducting element, a sixth unidirectional conducting element, an optocoupler isolation circuit, a first switch circuit, a second switch circuit, a third switch circuit and a control circuit; the voltages between phase A and phase B, phase B and phase C, and phase C and phase A are unidirectionally conducted by the unidirectional conducting elements, the corresponding switch circuits connect every two phases of the three-phase voltages according to the positive phase A voltage, the positive phase B voltage and the positive phase C voltage, the optocoupler isolation circuit generates a pulse width modulation signal according to the conduction of the switch circuit, the control circuit obtains the frequency parameter of the power supply according to the pulse width modulation signal to realize the detection of power phase loss and power failure, the circuit has a wide range of applicable environments, a simple circuit structure, low cost, high detection accuracy and reliability, and strong practicality.

Description

Technical Field

[0001] The invention belongs to the technical field of power supply for electrical equipment, and in particular relates to a power supply detection circuit and a robot. Background Art

[0002] Due to its outstanding advantages in power generation and distribution, it has been widely used in practice, especially in industrial production and manufacturing. The phase sequence of three-phase AC power is of great significance to the normal operation of electrical equipment. In many cases, power equipment is not allowed to have phase loss or reverse phase. Once the phase sequence is lost during normal operation of the equipment, it may cause damage to the equipment and make it unable to work or even burn out. Sudden power failure of electrical equipment may also lead to the risk of endangering the safe and reliable operation of the equipment. Therefore, it is necessary to detect the phase loss and power failure of electrical equipment in real time to ensure the safe and reliable operation of electrical equipment.

[0003] At present, the traditional phase loss detection technology mainly samples the voltage of the input AC power, and then compares the voltage through a comparator to monitor the state of the input AC power. This technology has very high requirements for the voltage range and is not suitable for occasions with severe voltage fluctuations. At the same time, the existing technology requires additional power supply to the comparator, the circuit is complex, and the large number of components used leads to high cost and poor detection accuracy. In addition, the traditional phase loss detection circuit cannot realize the difference between phase loss and power failure detection, has a small scope of application, and has poor reliability.

[0004] Therefore, the traditional technical solution has the problem that when performing phase loss detection on electrical equipment, it is impossible to distinguish between power outage and phase loss, and the phase loss detection circuit structure is complex and costly, which is not suitable for situations with large voltage fluctuations, and the detection accuracy and reliability are poor. Summary of the invention

[0005] In view of this, the embodiments of the present invention provide a power supply detection circuit, method and robot, aiming to solve the problems existing in traditional technical solutions that when performing phase loss detection on electrical equipment, it is impossible to distinguish between power failure and phase loss, and the phase loss detection circuit has a complex structure and high cost, is not suitable for situations with large voltage fluctuations, and has poor detection accuracy and reliability.

[0006] A first aspect of an embodiment of the present invention provides a power supply detection circuit, the power supply detection circuit comprising:

[0007] A first unidirectional conductive element is connected to the A phase of the power source and the first busbar, and is configured to unidirectionally conduct the voltage between the A phase and the B phase;

[0008] a third unidirectional conductive element, connected to the B phase of the power supply and the first bus, and configured to unidirectionally conduct the voltage between the B phase and the C phase;

[0009] A fifth unidirectional conducting element, connected to the C phase of the power source and the first bus, and configured to unidirectionally conduct the voltage between the C phase and the A phase;

[0010] A second unidirectional conductive element is connected to the A phase of the power supply and the third bus, and is configured to unidirectionally conduct the voltage between the C phase and the A phase;

[0011] A fourth unidirectional conducting element, connected to the B phase of the power supply and the third bus, and configured to unidirectionally conduct the voltage between the A phase and the B phase;

[0012] a sixth unidirectional conducting element, connected to the C phase of the power supply and the third bus, and configured to unidirectionally conduct the voltage between the B phase and the C phase;

[0013] A first switch circuit is connected to the A phase of the power supply, the second bus and the third bus, and is configured to conduct the voltage between the A phase and the B phase according to the voltage of the A phase;

[0014] a second switch circuit connected to the B phase of the power supply, the second bus and the third bus, and configured to conduct the voltage between the B phase and the C phase according to the voltage of the B phase;

[0015] a third switch circuit connected to the C phase of the power supply, the second bus and the third bus, and configured to conduct the voltage between the C phase and the A phase according to the voltage of the C phase;

[0016] an optical coupling isolation circuit connected to the first bus and the second bus, and configured to generate a pulse width modulation signal according to the connection of the voltage between the A phase and the B phase, the connection of the voltage between the B phase and the C phase, and the connection of the voltage between the C phase and the A phase;

[0017] The control circuit is connected to the optical coupling isolation circuit and is configured to obtain the frequency parameter of the power supply according to the pulse width modulation signal.

[0018] In one embodiment, the power detection circuit further includes:

[0019] The first filter circuit is connected to the second bus and the third bus, and is configured to filter and reduce noise on the voltage between the second bus and the third bus.

[0020] In one embodiment, the power detection circuit further includes:

[0021] A first voltage-dividing protection circuit is connected to the A phase of the power supply, the first unidirectional conducting element, the second unidirectional conducting element and the first switch circuit, and is configured to perform voltage-dividing protection on the voltage between the A phase and the B phase;

[0022] A second voltage-dividing protection circuit is connected to the B phase of the power supply, the third unidirectional conducting element, the fourth unidirectional conducting element and the second switch circuit, and is configured to perform voltage-dividing protection on the voltage of the B phase and the C phase;

[0023] The third voltage-dividing protection circuit is connected to the B phase of the power supply, the fifth unidirectional conducting element, the sixth unidirectional conducting element and the third switch circuit, and is configured to perform voltage-dividing protection on the voltage of the C phase and the A phase.

[0024] In one embodiment, the power detection circuit further includes:

[0025] a second filtering circuit, connected to the first bus, the third bus and the optical coupling isolation circuit, and configured to filter and reduce noise on the voltage between the first bus and the second bus;

[0026] The first voltage stabilizing circuit is connected to the first bus, the third bus and the optocoupler isolation circuit, and is configured to stabilize the voltage between the first bus and the third bus.

[0027] In one embodiment, the power detection circuit further includes:

[0028] The first current limiting protection circuit is connected to the first bus and the optocoupler isolation circuit, and is configured to perform current limiting protection on the voltage on the first bus.

[0029] In one embodiment, the power detection circuit further includes:

[0030] An indication circuit is connected to the optocoupler isolation circuit, the first switch circuit, the second switch circuit and the third switch circuit, and is configured to indicate according to the connectivity of the voltage between the A phase and the B phase, the connectivity of the voltage between the B phase and the C phase, and the connectivity of the voltage between the C phase and the A phase.

[0031] In one embodiment, the power detection circuit further includes:

[0032] The third filtering circuit is connected to the optical coupling isolation circuit and the control circuit, and is configured to filter and reduce noise on the pulse width modulation signal.

[0033] In one embodiment, the power detection circuit further includes:

[0034] The surge protection circuit is connected to the optical coupling isolation circuit and the control circuit, and is configured to perform surge pulse protection and electrostatic protection on the pulse width modulation signal.

[0035] In one embodiment, the switch circuit includes: a first capacitor, a second capacitor, a first resistor, a second resistor and a first transistor;

[0036] The first end of the first capacitor and the first end of the second capacitor are connected to phase A of the power supply, the second end of the first capacitor is connected to the second end of the first resistor and the second end of the second resistor, the second end of the second capacitor is connected to the first end of the first resistor and the base of the first transistor, the emitter of the first transistor is connected to the first end of the second resistor, the collector of the first transistor is connected to the second bus, and the second end of the second resistor is connected to the third bus.

[0037] A second aspect of the embodiments of the present invention provides a robot, comprising the power detection circuit described above.

[0038] The above-mentioned embodiment realizes phase loss detection of input multi-phase AC power through a unidirectional conducting component, a switching circuit, an optocoupler isolation circuit and a control circuit, and can also realize power-off detection of multi-phase power and unidirectional power. It is suitable for power environments with severe voltage fluctuations. There is no need to set up a DC power supply to power the phase loss detection and power-off power supply detection circuits. The circuit structure is simple, cost is saved, and the detection accuracy and stability and reliability are high, and the practicability is strong. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0040] Figure 1 A schematic diagram of a power supply detection circuit provided in an embodiment of the present invention;

[0041] Figure 2 Another structural schematic diagram of a power supply detection circuit provided in an embodiment of the present invention;

[0042] Figure 3 Another structural schematic diagram of a power supply detection circuit provided in an embodiment of the present invention;

[0043] Figure 4 Another structural schematic diagram of a power supply detection circuit provided in an embodiment of the present invention;

[0044] Figure 5 Another structural schematic diagram of a power supply detection circuit provided in an embodiment of the present invention;

[0045] Figure 6 Another structural schematic diagram of a power supply detection circuit provided in an embodiment of the present invention;

[0046] Figure 7 Another structural schematic diagram of a power supply detection circuit provided in an embodiment of the present invention;

[0047] Figure 8 Another structural schematic diagram of a power supply detection circuit provided in an embodiment of the present invention;

[0048] Fig. 9 An exemplary circuit schematic diagram of a power detection circuit provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0050] See also Figure 1 , a schematic diagram of a power supply detection circuit provided by an embodiment of the present invention, for the sake of convenience of explanation, only the part related to the present embodiment is shown, which is described in detail as follows:

[0051] A power supply detection circuit includes: a first unidirectional conducting element 11, a second unidirectional conducting element 12, a third unidirectional conducting element 13, a fourth unidirectional conducting element 14, a fifth unidirectional conducting element 15, a sixth unidirectional conducting element 16, an optocoupler isolation circuit 20, a first switch circuit 17, a second switch circuit 18, a third switch circuit 19 and a control circuit 21.

[0052] The first unidirectional conducting element 11 is connected to the A phase of the power supply and the first bus M1, and is configured to unidirectionally conduct the voltage between the A phase and the B phase; the third unidirectional conducting element 13 is connected to the B phase of the power supply and the first bus M1, and is configured to unidirectionally conduct the voltage between the B phase and the C phase; the fifth unidirectional conducting element 15 is connected to the C phase of the power supply and the first bus M1, and is configured to unidirectionally conduct the voltage between the C phase and the A phase; the second unidirectional conducting element 12 is connected to the A phase of the power supply and the third bus M3, and is configured to unidirectionally conduct the voltage between the C phase and the A phase; the fourth unidirectional conducting element 14 is connected to the B phase of the power supply and the third bus M3, and is configured to unidirectionally conduct the voltage between the A phase and the B phase; the sixth unidirectional conducting element 16 is connected to the C phase of the power supply and the third bus M3, and is configured to unidirectionally conduct the voltage between the B phase and the C phase.

[0053] The first switch circuit 17 is connected to phase A of the power supply, the second bus M2 and the third bus M3, and is configured to conduct the voltage between phase A and phase B according to the voltage of phase A; the second switch circuit 18 is connected to phase B of the power supply, the second bus M2 and the third bus M3, and is configured to conduct the voltage between phase B and phase C according to the voltage of phase B; the third switch circuit 19 is connected to phase C of the power supply, the second bus M2 and the third bus M3, and is configured to conduct the voltage between phase C and phase A according to the voltage of phase C.

[0054] The optocoupler isolation circuit 20 is connected to the first bus M1 and the second bus M2, and is configured to generate a pulse width modulation signal according to the connection of the voltage between phase A and phase B, the connection of the voltage between phase B and phase C, and the connection of the voltage between phase C and phase A; the control circuit 21 is connected to the optocoupler isolation circuit 20, and is configured to obtain the frequency parameters of the power supply according to the pulse width modulation signal.

[0055] In a specific implementation, phase A of the power supply, phase B of the power supply, and phase C of the power supply together constitute a three-phase power supply connected in a triangle. The voltage output by the power supply is three-phase alternating current, and the waveforms of the three-phase alternating current are all sinusoidal waves. The three have the same amplitude and frequency, and the phases are 120 degrees apart from each other. A circuit for conducting the voltage between phase A and phase B is formed by the first unidirectional conducting element 11, the first bus M1, the optocoupler isolation circuit 20, the second bus M2, the first switch circuit 17, the third bus M3 and the fourth unidirectional conducting element 14; a circuit for conducting the voltage between phase B and phase C is formed by the third unidirectional conducting element 13, the first bus M1, the optocoupler isolation circuit 20, the second bus M2, the second switch circuit 18, the third bus M3 and the sixth unidirectional conducting element 16; a circuit for conducting the voltage between phase C and phase A is formed by the fifth unidirectional conducting element 15, the first bus M1, the optocoupler isolation circuit 20, the second bus M2, the third switch circuit 19, the third bus M3 and the second unidirectional conducting element 12; thereby forming a circuit in which the three-phase alternating current of the power supply is conducted in pairs. At the same time, the three-phase voltage can also be rectified through the unidirectional conducting element, the switching circuit conducts the positive voltage and turns off the negative voltage, forming a periodic on-off control with a certain switching frequency, so that the optocoupler isolation circuit 20 generates a pulse width modulation signal according to the conduction and shutdown of the three-phase voltage, and the controller of the control circuit 21 (such as a single-chip microcomputer, a microprocessor) analyzes and calculates the frequency parameters of the power supply according to the pulse width modulation signal. The frequency parameters carry frequency value information, and the control circuit 21 then judges the phase loss and power failure of the three-phase power supply, as well as the power failure of the two-phase power supply and the single-phase power supply according to the frequency value information. For example, when the frequency value analyzed and calculated by the controller of the control circuit 21 is within the first preset frequency range, it is judged that the three-phase input AC power is not missing a phase; if the frequency value is within the second preset frequency range, it is judged that the input AC power is missing a phase; if the frequency value is within the third preset frequency range, it is judged that the input AC power is off. Since the frequency value of the alternating current used in my country is 50HZ, it is optional that the first preset frequency range is 148HZ to 152HZ, the second preset frequency range is 98HZ to 102HZ, and the third preset frequency range is 0HZ to 2HZ.

[0056] Optionally, the control circuit 21 includes at least one of a single-chip microcomputer, a central processing unit (CPU), a digital signal processor (DSP), a central control unit (MCU), a field programmable gate array (FPGA), a complex programmable logic device (CPLD), an application specific integrated circuit (ASIC), other general-purpose processors, and other programmable logic devices. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc., so that the control circuit 21 has sufficient computing and processing capabilities, can analyze, calculate, judge and control according to the pulse width modulation signal, and meet the needs of multi-phase power loss detection and power-off detection.

[0057] The embodiment of the present invention can realize phase loss detection of multi-phase AC power without relying on a large number of comparators and a large number of optical couplers, and can realize power-off detection of three-phase power, two-phase power and unidirectional power at the same time. It can be applicable to power environments with severe voltage fluctuations and has a wide range of adaptability. There is no need to set up a DC power supply to power the power detection circuit. The circuit structure is simple and the cost is saved. Phase loss detection is realized by the switching frequency of the switching circuit to avoid the influence of power loss on phase loss detection. The detection accuracy and stability reliability are high and the practicability is strong.

[0058] See also Figure 2 In one embodiment, the power detection circuit further includes: a first filtering circuit 22.

[0059] The first filter circuit 22 is connected to the second bus M2 and the third bus M3 and is configured to filter and reduce noise on the voltage between the second bus M2 and the third bus M3.

[0060] In a specific implementation, the optocoupler isolation circuit 20 is specifically configured to generate a pulse width modulation signal according to the voltage between the second bus M2 and the third bus M3 after filtering and noise reduction. After filtering and noise reduction of the voltage between each two phases of the single-phase conducting element unidirectionally conducted by the first filter circuit 22, the optocoupler isolation circuit 20 performs photoelectric conversion to generate a pulse width modulation signal, further improving the accuracy and reliability of analyzing and calculating the frequency parameters of the power supply according to the pulse width modulation signal to perform phase loss detection and power failure detection.

[0061] See also Figure 3 In one embodiment, the power detection circuit further includes: a first voltage division protection circuit 23 , a second voltage division protection circuit 24 and a third voltage division protection circuit 25 .

[0062] The first voltage-dividing protection circuit 23 is connected to the A phase of the power supply, the first unidirectional conducting element 11, the second unidirectional conducting element 12 and the first switching circuit 17, and is configured to perform voltage-dividing protection on the voltage between the A phase and the B phase; the second voltage-dividing protection circuit 24 is connected to the B phase of the power supply, the third unidirectional conducting element 13, the fourth unidirectional conducting element 14 and the second switching circuit 18, and is configured to perform voltage-dividing protection on the voltage between the B phase and the C phase; the third voltage-dividing protection circuit 25 is connected to the B phase of the power supply, the fifth unidirectional conducting element 15, the sixth unidirectional conducting element 16 and the third switching circuit 19, and is configured to perform voltage-dividing protection on the voltage between the C phase and the A phase.

[0063] In a specific implementation, the voltage-dividing protection circuit can be used to implement voltage-dividing protection for each phase of input AC power, so as to prevent large voltage shocks and loss of electronic components in the circuit, thereby improving the practicality and service life of the device.

[0064] See also Figure 4 In one embodiment, the power detection circuit further includes: a second filtering circuit 26 and a first voltage stabilizing circuit 27 .

[0065] The second filtering circuit 26 is connected to the first bus M1, the third bus M3 and the optocoupler isolation circuit 20, and is configured to filter and reduce noise on the voltage between the first bus M1 and the third bus M3; the first voltage stabilizing circuit 27 is connected to the first bus M1, the third bus M3 and the optocoupler isolation circuit 20, and is configured to stabilize the voltage between the first bus M1 and the third bus M3.

[0066] In a specific implementation, the optocoupler isolation circuit 20 is specifically configured to generate a pulse width modulation signal according to the voltage between the first bus M1 and the third bus M3 after filtering and stabilization. After filtering and noise reduction processing is performed on the voltage between the first bus M1 and the third bus M3 by the second filtering circuit 26, the voltage between the first bus M1 and the third bus M3 is further stabilized by the first voltage stabilizing circuit 27, so that the voltage output to the optocoupler isolation circuit 20 is stable, smooth, and has low noise interference, so that the optocoupler isolation circuit 20 generates a stable and high-precision pulse width modulation signal, thereby improving the accuracy and stability reliability of the control circuit 21 to obtain the frequency parameters of the power supply according to the pulse width modulation signal to detect and judge the phase loss or power failure of the three-phase power supply.

[0067] See also Figure 5 In one embodiment, the power detection circuit further includes: a first current limiting protection circuit 28.

[0068] The first current limiting protection circuit 28 is connected to the first bus M1 and the optocoupler isolation circuit 20 , and is configured to perform current limiting protection on the voltage on the first bus M1 .

[0069] In a specific implementation, the optocoupler isolation circuit 20 is specifically configured to generate a pulse width modulation signal according to the voltage on the first bus after current limiting protection. The first current limiting protection circuit 28 can prevent a large current from flowing through the optocoupler isolation circuit 20, thereby damaging the components of the optocoupler isolation circuit 20, thereby improving the stability, reliability and practicality of phase loss detection and power failure detection.

[0070] See also Figure 6 In one embodiment, the power detection circuit further includes: an indication circuit 29.

[0071] The indication circuit 29 is connected to the optocoupler isolation circuit 20, the first switch circuit 17, the second switch circuit 18 and the third switch circuit 19, and is configured to indicate according to the connectivity of the voltage between phase A and phase B, the connectivity of the voltage between phase B and phase C, and the connectivity of the voltage between phase C and phase A.

[0072] In a specific implementation, the indicator circuit 29 includes a light-emitting diode, and the indicator circuit 29 is connected in series on the second bus M2, that is, connected in series between the optocoupler isolation circuit 20 and the first switch circuit 17, the second switch circuit 18 and the third switch circuit 19, and can display the phase loss and power-off status of the three-phase alternating current output by the three-phase power supply, so that the tester can understand the test results in a timely and intuitive manner.

[0073] See also Figure 7 In one embodiment, the power detection circuit further includes: a third filtering circuit 30.

[0074] The third filter circuit 30 is connected to the optical coupling isolation circuit 20 and the control circuit 21 and is configured to filter and reduce noise on the pulse width modulation signal.

[0075] In a specific implementation, the pulse width modulation signal generated and output by the optocoupler isolation circuit 20 can be filtered and denoised by the third filtering circuit 30, further improving the control circuit 21 to generate frequency parameters based on the pulse width modulation signal to determine the phase loss or power failure of the three-phase power supply, thereby improving the accuracy and stability and reliability of phase loss detection and power failure detection.

[0076] See also Figure 8 In one embodiment, the power detection circuit further includes: a surge protection circuit 31.

[0077] The surge protection circuit 31 is connected to the optocoupler isolation circuit 20 and the control circuit 21 , and is configured to perform surge pulse protection and electrostatic protection on the pulse width modulation signal.

[0078] In a specific implementation, when the surge protection circuit 31 is subjected to a high-energy instantaneous overvoltage pulse, its working impedance can immediately drop to a very low conduction value, allowing large current to pass through and clamping the voltage to a predetermined level, thereby effectively protecting the precision components in the electronic circuit from damage, thereby improving the safety and reliability of the phase loss detection and power-off detection circuits.

[0079] See also Fig. 9 In one embodiment, the first switch circuit 17 includes: a first capacitor C1, a second capacitor C2, a first resistor R11, a second resistor R12 and a first transistor Q1.

[0080] The first end of the first capacitor C1 and the first end of the second capacitor C2 are connected to phase A of the power supply, the second end of the first capacitor C1 is connected to the second end of the first resistor R11 and the second end of the second resistor R12, the second end of the second capacitor C2 is connected to the first end of the first resistor R11 and the base of the first transistor Q1, the emitter of the first transistor Q1 is connected to the first end of the second resistor R12, the collector of the first transistor Q1 is connected to the second bus M2, and the second end of the second resistor R12 is connected to the third bus M3.

[0081] In a specific implementation, the second switch circuit 18 includes: a third capacitor C3, a fourth capacitor C4, a third resistor R13, a fourth resistor R14 and a second transistor Q2.

[0082] A first end of the third capacitor C3 and the fourth capacitor C4 are connected to phase B of the power supply, a second end of the third capacitor C3 is connected to a second end of the third resistor R13 and a second end of the fourth resistor R14, a second end of the fourth capacitor C4 is connected to a first end of the third resistor R13 and a base of the second transistor Q2, an emitter of the second transistor Q2 is connected to a first end of the fourth resistor R14, a collector of the second transistor Q2 is connected to the second bus M2, and a second end of the fourth resistor R14 is connected to the third bus M3.

[0083] The third switch circuit 19 includes a fifth capacitor C5, a sixth capacitor C6, a fifth resistor R15, a sixth resistor R16 and a third transistor Q3.

[0084] The first end of the fifth capacitor C5 and the sixth capacitor C6 are connected to the C phase of the power supply, the second end of the fifth capacitor C5 is connected to the second end of the fifth resistor R15 and the second end of the sixth resistor R16, the second end of the sixth capacitor C6 is connected to the first end of the fifth resistor R15 and the base of the third transistor Q3, the emitter of the third transistor Q3 is connected to the first end of the sixth resistor R16, the collector of the third transistor Q3 is connected to the second bus M2, and the second end of the sixth resistor R16 is connected to the third bus M3.

[0085] In one embodiment, please refer to Figure 9, in one embodiment, the optocoupler isolation circuit 20 includes an optocoupler isolator U1. The anode of the optocoupler isolator U1 is connected to the first bus M1, the cathode of the optocoupler isolator U1 is connected to the second bus M2, and the collector of the optocoupler isolator U1 and the emitter of the optocoupler isolator U1 together constitute the pulse width modulation signal output end of the optocoupler isolation circuit 20.

[0086] In a specific implementation, the optocoupler isolator U1 integrates the light-emitting device and the photosensitive receiving device. The electrical signal applied to the light-emitting device is the input signal of the optocoupler isolator U1, and the signal output by the receiving device is the output signal of the optocoupler isolator U1. When the optocoupler isolator U1 has an input signal applied to the light-emitting device (such as a light-emitting diode) of the optocoupler isolator U1 and the circuit where the light-emitting device is located is turned on, the photosensitive receiving device (such as a phototransistor) of the optocoupler isolator U1 generates a photocurrent when illuminated by light, so that the output end of the optocoupler isolator U1 outputs a corresponding electrical signal, so that the optocoupler isolator U1 generates a pulse width modulation signal according to the connection of the voltage between phase A and phase B, the connection of the voltage between phase B and phase C, and the connection of the voltage between phase C and phase A, so that the control circuit 21 calculates the frequency parameters of the power supply according to the pulse width modulation signal to perform accurate and reliable phase loss detection and power-off detection.

[0087] In one embodiment, please refer to Figure 9, in one embodiment, the unidirectional conductive element includes a Schottky diode.

[0088] The first unidirectional conducting element 11 is a first Schottky diode D1, the anode of the first Schottky diode D1 is connected to the A phase of the power supply, and the cathode of the first Schottky diode D1 is connected to the first bus M1; the second unidirectional conducting element 12 is a second Schottky diode D2, the cathode of the second Schottky diode D2 is connected to the A phase of the power supply, and the anode of the second Schottky diode D2 is connected to the third bus M3; the third unidirectional conducting element 13 is a third Schottky diode D3, the anode of the third Schottky diode D3 is connected to the B phase of the power supply, and the cathode of the third Schottky diode D3 is connected to the first bus M1; The fourth unidirectional conducting element 14 is a fourth Schottky diode D4, the cathode of which is connected to the B phase of the power supply, and the anode of which is connected to the third bus M3; the fifth unidirectional conducting element 15 is a fifth Schottky diode D5, the anode of which is connected to the C phase of the power supply, and the cathode of which is connected to the first bus M1; the sixth unidirectional conducting element 16 is a sixth Schottky diode D6, the cathode of which is connected to the C phase of the power supply, and the anode of which is connected to the third bus M3.

[0089] See also Fig. 9In a specific implementation, the control circuit 21 is a control circuit arranged on the robot arm. Optionally, the control circuit 21 includes a microcontroller, such as STM32. The first voltage-dividing protection circuit 23 includes a seventh resistor R1, the second voltage-dividing protection circuit 24 includes an eighth resistor R2, and the third voltage-dividing protection circuit 25 includes a ninth resistor R3. The seventh resistor R1, the eighth resistor R2, and the ninth resistor R3 are used to respectively perform voltage-dividing protection on the A phase of the power supply, the B phase of the power supply, and the C phase of the power supply to prevent the voltage loaded on the unidirectional conducting element and the switching circuit from being too large, causing serious heating or even burning components and affecting the normal operation of the circuit, thereby improving the safety and reliability of the power supply detection circuit. Optionally, in order to prevent the voltage-dividing circuit from heating up seriously and to achieve effective heat dissipation and cooling, the first voltage-dividing protection circuit 23, the second voltage-dividing protection circuit 24, and the third voltage-dividing protection circuit 25 can all be composed of a plurality of voltage-dividing resistors connected in series.

[0090] The first filter circuit 22 includes a seventh capacitor C7, a first end of the seventh capacitor C7 is connected to the second bus M2, and a second end of the seventh capacitor C7 is connected to the third bus M3. The second filter circuit 26 includes an eighth capacitor C8, a first end of the eighth capacitor C8 is connected to the first bus M1, and a second end of the eighth capacitor C8 is connected to the third bus M3. The first voltage stabilizing circuit 27 includes a voltage stabilizing tube D7, a cathode of the voltage stabilizing tube D7 is connected to the first bus M1, and an anode of the voltage stabilizing tube D7 is connected to the third bus M3. The first current limiting protection circuit 28 includes a tenth resistor R10, and the tenth resistor R10 is connected in series between the first bus M1 and the anode of the optocoupler isolator U1. The third filter circuit 30 includes a ninth capacitor C9, a first end of the ninth capacitor C9 is connected to the collector of the optocoupler isolator U1, and a second end of the ninth capacitor C9 and the emitter of the optocoupler isolator U1 are connected to the power supply ground. The surge protection circuit 31 includes a transient suppression diode D8. The indication circuit 29 includes a light emitting diode D9.

[0091] The following will be combined Fig. 9 A brief description of the working principle of the power detection circuit:

[0092] The first unidirectional conduction element 11 (first Schottky diode D1) conducts unidirectional conduction of the voltage between phase A and phase B, and transmits it to the collector of the first field effect transistor Q1 through the first bus M1, the light-emitting diode of the optical coupler isolator U1, and the second bus M2. The first field effect transistor Q1 is turned on according to the forward voltage of phase A, and then conducts unidirectional conduction of the voltage between phase A and phase B through the third bus M3 and the fourth unidirectional conduction component 14 (fourth Schottky diode D4); the third unidirectional conduction element 13 (third Schottky diode D3) conducts unidirectional conduction of the voltage between phase B and phase C, and transmits it to the collector of the second field effect transistor Q2 through the first bus M1, the light-emitting diode of the optical coupler isolator U1, and the second bus M2. The second field effect transistor Q2 is turned on according to the forward voltage of phase B, and then unidirectionally conducts the voltage between phase B and phase C through the third bus M3 and the sixth unidirectional conduction component 16 (sixth Schottky diode D6); the fifth unidirectional conduction element 15 (fifth Schottky diode D5) unidirectionally conducts the voltage between phase C and phase A, and is transmitted to the collector of the third field effect transistor Q3 through the first bus M1, the light-emitting diode of the optical coupling isolator U1, and the second bus M2. The third field effect transistor Q3 is turned on according to the forward voltage of phase C, and then unidirectionally conducts the voltage between phase C and phase A through the third bus M3 and the second unidirectional conduction component 12 (second Schottky diode D2); the two-phase interconnection of three-phase alternating current is realized.

[0093] The voltage between phase A and phase B, the voltage between phase B and phase C, and the voltage between phase C and phase A are all transmitted through the first bus M1, the second bus M2, and the third bus M3. The seventh capacitor C7 filters and reduces noise on the voltage between the second bus M2 and the third bus M3 to filter out the noise interference of the voltage between the second bus M2 and the third bus M3; the eighth capacitor C8 filters and reduces noise on the voltage between the first bus M1 and the third bus M3 to filter out the noise (such as ripple noise) interference of the voltage between the first bus M1 and the third bus M3; the voltage regulator D7 stabilizes the voltage between the first bus M1 and the third bus M3, so that a smooth and stable voltage is output to the optocoupler isolator U1.

[0094] The first field effect transistor Q1 is turned on according to the positive voltage of phase A and is turned off according to the negative voltage of phase A, thereby periodically connecting or disconnecting the voltage between phase A and phase B at a certain frequency; the second field effect transistor Q2 periodically connects or disconnects the voltage between phase B and phase C at a certain frequency, and the third field effect transistor Q3 periodically connects or disconnects the voltage between phase C and phase A at a certain frequency, thereby forming a switching frequency that is consistent with or a multiple (for example, twice or three times) of the three-phase AC frequency of the power supply, so that the optocoupler isolator U1 performs electrical-optical-electrical conversion according to the conduction of the voltage between phase A and phase B, the conduction of the voltage between phase B and phase C, and the conduction of the voltage between phase C and phase A to generate a pulse width modulation signal, and the corresponding light-emitting diode D9 performs light indication according to the conduction of the voltage between phase A and phase B, the conduction of the voltage between phase B and phase C, and the conduction of the voltage between phase C and phase A, thereby indicating the phase loss or power-off state of the power supply. The ninth capacitor C9 performs filtering and noise reduction processing on the pulse width modulation signal to filter out noise interference in the pulse width modulation signal; the transient suppression diode D8 can withstand transient abnormal pulses and clamp the voltage to a predetermined level, effectively protecting the pulse width modulation signal from surges and electrostatics, so as to output a low-noise interference, high-precision, highly stable and reliable pulse width modulation signal to the control circuit 21. The control circuit 21 calculates the frequency parameters of the power supply according to the pulse width modulation signal, thereby realizing the three-phase AC phase loss detection and three-phase AC power failure, two-phase AC power failure and single-phase AC power failure detection of the power supply according to the frequency parameters of the power supply. There is no restriction on the AC frequency of the input circuit, and it can include the AC frequency of 50Hz / 60Hz±20% adopted by the global power supply; there is no restriction on the input AC voltage, and it can also include the AC voltage of 50VAC~300VAC adopted by the global power supply (the normal maximum fluctuation range of the international voltage is 90VAC~264VAC); there is no need to set a DC power supply to power the power supply detection circuit, which is suitable for the situation where the voltage fluctuation of the power supply is large, has a wide detection range, good environmental adaptability, simple circuit structure, low cost, and high safety and reliability.

[0095] A second aspect of an embodiment of the present invention provides a robot, comprising the power detection circuit described above.

[0096] In a specific implementation, the three-phase phase loss detection circuit and the power failure detection circuit can be applied to the control circuits of desktop-level robotic arms, multi-joint robotic arms and other robotic arms, as well as to the control circuits of robot robotic arms.

[0097] The embodiment of the present invention can realize phase loss detection for multi-phase alternating current, and simultaneously realize power failure detection for multi-phase alternating current and unidirectional alternating current, and can be applied to power environments with severe voltage fluctuations. The circuit structure is simple, cost is saved, and the detection accuracy, stability and reliability are high, and the practicability is strong.

[0098] Those skilled in the art will appreciate that the embodiments described herein and illustrated are non-limiting examples, and therefore may appreciate that the specific structural and functional details disclosed herein may be representative and do not necessarily limit the scope of the embodiments.

[0099] References throughout the specification to "various embodiments," "in an embodiment," "one embodiment," or "an embodiment," etc., mean that a particular feature, structure, or characteristic described with respect to the embodiment is included in at least one embodiment. Therefore, the appearance of the phrases "in various embodiments," "in some embodiments," "in one embodiment," or "in an embodiment," etc., in appropriate places throughout the specification do not necessarily refer to the same embodiment. In addition, particular features, structures, or characteristics may be combined in any appropriate manner in one or more embodiments. Therefore, particular features, structures, or characteristics shown or described with respect to one embodiment may be combined in whole or in part with features, structures, or characteristics of one or more other embodiments without assuming that such a combination is not an illogical or non-functional limitation.

[0100] Although certain embodiments are described above with a certain degree of detail, those skilled in the art may make many changes to the disclosed embodiments without departing from the scope of the present disclosure. Connection references (e.g., attachment, coupling, connection, etc.) should be interpreted broadly and may include intermediate members between the connection of elements and relative motion between elements. Therefore, connection references do not necessarily imply that two elements are directly connected / coupled and are in a fixed relationship with each other. The use of "for example" throughout the specification should be interpreted broadly and used to provide non-limiting examples of embodiments of the present disclosure, and the present disclosure is not limited to such examples. It is intended that all matters included in the above description or shown in the accompanying drawings should be interpreted as merely illustrative rather than restrictive. Changes in details or structure may be made without departing from the present disclosure.

[0101] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0102] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A power supply detection circuit, characterized in that: The power detection circuit comprises: A first unidirectional conductive element is connected to the A phase of the power source and the first busbar, and is configured to unidirectionally conduct the voltage between the A phase and the B phase; a third unidirectional conductive element, connected to the B phase of the power supply and the first bus, and configured to unidirectionally conduct the voltage between the B phase and the C phase; A fifth unidirectional conducting element, connected to the C phase of the power source and the first bus, and configured to unidirectionally conduct the voltage between the C phase and the A phase; A second unidirectional conductive element is connected to the A phase of the power supply and the third bus, and is configured to unidirectionally conduct the voltage between the C phase and the A phase; A fourth unidirectional conducting element, connected to the B phase of the power supply and the third bus, and configured to unidirectionally conduct the voltage between the A phase and the B phase; A sixth unidirectional conducting element, connected to the C phase of the power supply and the third bus, and configured to unidirectionally conduct the voltage between the B phase and the C phase; A first switch circuit is connected to the A phase of the power supply, the second bus and the third bus, and is configured to conduct the voltage between the A phase and the B phase according to the voltage of the A phase; a second switch circuit connected to the B phase of the power supply, the second bus and the third bus, and configured to conduct the voltage between the B phase and the C phase according to the voltage of the B phase; a third switch circuit connected to the C phase of the power supply, the second bus and the third bus, and configured to conduct the voltage between the C phase and the A phase according to the voltage of the C phase; an optical coupling isolation circuit connected to the first bus and the second bus, and configured to generate a pulse width modulation signal according to the connection of the voltage between the A phase and the B phase, the connection of the voltage between the B phase and the C phase, and the connection of the voltage between the C phase and the A phase; The control circuit is connected to the optical coupling isolation circuit and is configured to obtain the frequency parameter of the power supply according to the pulse width modulation signal.

2. The power supply detection circuit according to claim 1, characterized in that: The power detection circuit also includes: The first filter circuit is connected to the second bus and the third bus, and is configured to filter and reduce noise on the voltage between the second bus and the third bus.

3. The power detection circuit according to claim 1, characterized in that: The power detection circuit also includes: A first voltage-dividing protection circuit is connected to the A phase of the power supply, the first unidirectional conducting element, the second unidirectional conducting element and the first switch circuit, and is configured to perform voltage-dividing protection on the voltage between the A phase and the B phase; A second voltage-dividing protection circuit is connected to the B phase of the power supply, the third unidirectional conducting element, the fourth unidirectional conducting element and the second switch circuit, and is configured to perform voltage-dividing protection on the voltage of the B phase and the C phase; The third voltage-dividing protection circuit is connected to the B phase of the power supply, the fifth unidirectional conducting element, the sixth unidirectional conducting element and the third switch circuit, and is configured to perform voltage-dividing protection on the voltage of the C phase and the A phase.

4. The power detection circuit according to claim 1, characterized in that: The power detection circuit also includes: a second filtering circuit, connected to the first bus, the third bus and the optical coupling isolation circuit, and configured to filter and reduce noise on the voltage between the first bus and the second bus; The first voltage stabilizing circuit is connected to the first bus, the third bus and the optocoupler isolation circuit, and is configured to stabilize the voltage between the first bus and the third bus.

5. The power detection circuit according to claim 1, characterized in that: The power detection circuit also includes: The first current limiting protection circuit is connected to the first bus and the optocoupler isolation circuit, and is configured to perform current limiting protection on the voltage of the first bus.

6. The power detection circuit according to claim 1, characterized in that: The power detection circuit also includes: An indication circuit is connected to the optocoupler isolation circuit, the first switch circuit, the second switch circuit and the third switch circuit, and is configured to indicate according to the connectivity of the voltage between the A phase and the B phase, the connectivity of the voltage between the B phase and the C phase, and the connectivity of the voltage between the C phase and the A phase.

7. The power detection circuit according to claim 1, characterized in that: The power detection circuit also includes: The third filtering circuit is connected to the optical coupling isolation circuit and the control circuit, and is configured to filter and reduce noise on the pulse width modulation signal.

8. The power detection circuit according to claim 1, characterized in that: The power detection circuit also includes: The surge protection circuit is connected to the optical coupling isolation circuit and the control circuit, and is configured to perform surge pulse protection and electrostatic protection on the pulse width modulation signal.

9. The power detection circuit according to claim 1, characterized in that: The switch circuit comprises: a first capacitor, a second capacitor, a first resistor, a second resistor and a first transistor; The first end of the first capacitor and the first end of the second capacitor are connected to phase A of the power supply, the second end of the first capacitor is connected to the second end of the first resistor and the second end of the second resistor, the second end of the second capacitor is connected to the first end of the first resistor and the base of the first transistor, the emitter of the first transistor is connected to the first end of the second resistor, the collector of the first transistor is connected to the second bus, and the second end of the second resistor is connected to the third bus.

10. A robot, characterized in that: The robot comprises the power detection circuit according to any one of claims 1 to 9.

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