Energy consumption braking circuit and driver

Abstract

The utility model relates to an energy consumption braking circuit and a driver. The energy consumption braking circuit comprises a braking pipe, a braking resistor connected with one end of the braking pipe, a braking pipe voltage detection unit, a fault signal shielding unit and a processing unit connected with a first output end. The brake pipe voltage detection unit is configured to control the output level of the first output end according to the collector-emitter voltage drop of the brake pipe; wherein the first output end outputs a first level under the condition of overcurrent of a brake pipe when a brake signal indicates braking, and otherwise, outputs a second level; the first level is one of high and low levels, and the second level is the other one of the high and low levels; the fault signal shielding unit is connected with the first output end and is configured to adjust the level state of the first output end to be the same as the second level all the time when the braking signal does not indicate braking; the logic of the signal is simplified, so that the abnormity prompted by the first output end can be quickly responded in some implementation processes.

Description

Technical Field

[0001] The utility model relates to the field of drivers, in particular to an energy-consuming braking circuit and a driver. Background Art

[0002] For various motor load drivers, during the rapid deceleration and shutdown process of the motor, the motor acts as a generator, and the back electromotive force reversely charges the bus capacitor of the driver. If not handled, the motor reverse charges the bus capacitor of the driver during rapid deceleration, and the bus voltage is likely to rise rapidly, causing internal damage to the driver. Based on this, an energy-consuming braking circuit is usually provided in the driver. By detecting the bus voltage of the driver and reaching a predetermined threshold, the driver uses a braking (brake) resistor inside the driver to quickly release the energy of the motor's reverse charging bus capacitor in the form of heat. The regenerative braking energy release is connected or disconnected by opening or closing the built-in braking IGBT (Insulate-Gate Bipolar Transistor) of the driver.

[0003] In practical applications, whether overcurrent occurs is usually determined by the voltage of the braking resistor or the braking IGBT. However, the voltage of the braking resistor or the braking IGBT is different in the braking and non-braking states, and the feedback signal generated by overcurrent detection also has different signal logic in the braking and non-braking states, which makes the signal logic of the circuit complex and is not conducive to efficiently handling overcurrent anomalies. Utility Model Content

[0004] In view of the deficiencies of the above-mentioned related technologies, the purpose of the present application is to provide an energy-consuming braking circuit and driver, aiming to solve the problem that the feedback signal generated by detecting overcurrent has different signal logics in the braking and non-braking states, resulting in complex signal logic of the circuit.

[0005] An energy-consuming braking circuit comprises:

[0006] A brake pipe, a control electrode of which is connected to a brake signal and is turned on to perform energy-consuming braking when the brake signal indicates braking;

[0007] A brake resistor connected to one end of the brake pipe, when energy-consuming braking is performed, the brake pipe is turned on, and the brake resistor is connected to the brake circuit to consume the energy generated by braking;

[0008] A brake pipe voltage detection unit, comprising a first output terminal; the brake pipe voltage detection unit is configured to control an output level of the first output terminal according to a collector-emitter voltage drop of the brake pipe; wherein the first output terminal outputs a first level when the brake signal indicates braking and the brake pipe is overcurrent, otherwise, outputs a second level; the first level is one of a high level and a low level, and the second level is another of the high level and the low level;

[0009] a fault signal shielding unit connected to the first output terminal, configured to adjust the level state of the first output terminal to always be the same as the second level when the braking signal does not indicate braking;

[0010] A processing unit connected to the first output terminal.

[0011] The fault signal shielding unit of the dynamic braking circuit makes the first output end of the brake pipe voltage detection unit present the first level only when overcurrent occurs during braking, and always maintain the second level in other states. Therefore, at any time, as long as the level state of the first output end is detected to be the first level, it means that the dynamic braking circuit has an abnormality, which simplifies the logic of the signal. In some implementation processes, it is also conducive to a quick response to the abnormality prompted by the first output end.

[0012] Optionally, the processing unit comprises an interrupt input terminal, and the first output terminal is connected to the interrupt input terminal.

[0013] Optionally, the fault signal shielding unit includes a delay subunit and a non-delay subunit;

[0014] The delay subunit is configured to continue to maintain the level state of the first output terminal to be the same as the second level within a delay time when the brake signal starts to indicate braking; the delay time is greater than the response time of the dynamic braking circuit to the brake signal; after the delay time, the output level of the first output terminal is determined according to the collector-emitter voltage drop of the brake pipe;

[0015] The non-delay subunit is configured to immediately adjust the level state of the first output terminal to be the same as the second level when the braking signal changes from indicating braking to not indicating braking.

[0016] Optionally, the energy-consuming braking circuit also includes an optocoupler isolation driving unit, one of the input ends of the optocoupler isolation driving unit is connected to the braking signal, and the output end thereof is connected to the control electrode of the brake pipe to output a preset voltage to drive the brake pipe to conduct when the braking signal indicates braking.

[0017] Optionally, the brake pipe voltage detection unit further includes a second output terminal, and the brake pipe voltage detection unit is further configured to control an output level of the second output terminal according to a collector-emitter voltage drop of the brake pipe; wherein the second output terminal outputs a third level under normal circumstances when the brake signal indicates braking, and outputs a fourth level when the brake pipe is disconnected; when the brake signal does not indicate braking, the second output terminal outputs a fourth level under normal circumstances, and outputs the third level when the brake pipe is short-circuited; the third level is one of a high level and a low level, and the fourth level is the other of the high level and the low level;

[0018] The processing unit is also connected to the second output end, and the first output end and the second output end are connected to different ports of the processing unit.

[0019] Optionally, the brake pipe voltage detection unit includes an optocoupler isolator unit, the output end of the optocoupler isolator unit serves as the second output end, and one of the input ends of the optocoupler isolator unit is connected between the brake pipe and the brake resistor to control the level of the output end according to the collector-emitter voltage drop of the brake pipe.

[0020] Optionally, the brake pipe voltage detection unit includes a first transistor, a control electrode of the first transistor is connected to the second output end, and one electrode of the first transistor serves as the first output end;

[0021] The fault signal shielding unit includes a second transistor, a control electrode of the second transistor is connected to the braking signal, and one of the other two electrodes is connected to the first output end; the second transistor is turned on when the braking signal does not indicate braking, so as to turn on the circuit where the first output end is located, thereby adjusting the level of the first output end to always be the same as the second level; the second transistor is cut off when the braking signal indicates braking, so that the output level of the first output end is determined according to the collector-emitter voltage drop of the brake tube.

[0022] Optionally, the fault signal shielding unit further includes an RC delay circuit, the RC delay circuit includes a first anti-reverse diode and a resistor and a capacitor that cooperate to form a delay, and the braking signal is connected to the control electrode of the second transistor through the RC delay circuit;

[0023] When the braking signal starts to indicate braking, the RC delay circuit continues to keep the second transistor turned on during the delay time; the delay time is greater than the response time of the energy-consuming braking circuit to the braking signal.

[0024] Optionally, the fault signal shielding unit further includes a non-delay circuit connected in parallel with the RC delay circuit, and the non-delay circuit includes a second anti-reverse diode and a resistor;

[0025] When the braking signal is switched to no longer indicate braking, the braking signal passes through the loop where the non-delay circuit is located so that the second transistor is immediately switched to a cut-off state.

[0026] Based on the same inventive concept, the present application also provides a driver, including the above-mentioned energy-consuming braking circuit.

[0027] The fault signal shielding unit of the dynamic braking circuit adopted by the above driver makes the first output end of the brake pipe voltage detection unit present the first level only when overcurrent occurs during braking, and always maintain the second level in other states. Therefore, at any time, as long as the level state of the first output end is detected to be the first level, it means that an abnormality has occurred in the dynamic braking circuit, which simplifies the logic of the signal. In some implementation processes, it is also conducive to a quick response to the abnormality prompted by the first output end, making the driver more reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A schematic diagram of the structure of the energy-consuming braking circuit provided in the embodiment of the utility model;

[0029] Figure 2 A schematic diagram of the connection between the brake resistor and the brake pipe provided in the embodiment of the utility model;

[0030] Figure 3 Another structural schematic diagram of the energy-consuming braking circuit provided by an embodiment of the utility model;

[0031] Figure 4 A schematic diagram of the structure of a driver provided in an embodiment of the utility model;

[0032] Figure 5 A schematic diagram of the structure of an exemplary energy-consuming braking circuit provided in an embodiment of the utility model;

[0033] Figure 6 A circuit diagram of an exemplary energy-consuming braking circuit provided in an embodiment of the utility model;

[0034] Figure 7 A schematic diagram of a curve showing the relationship between the collector and emitter voltages of a brake tube provided in an embodiment of the utility model;

[0035] Description of reference numerals:

[0036] 101-brake pipe voltage detection unit; 102-fault signal shielding unit; 103-processing unit; 104-optical coupler isolation drive unit; 105-rectification and EMC filter unit; 106-bus capacitor; 107-three-phase inverter bridge; 108-load motor; 1011-optical coupler isolation subunit; 1021-RC delay circuit; 1022-non-delay circuit; sign-brake signal; VIN-mains power; VDC-bus; VDD-5V power supply; VCC-15V power supply; R-brake resistor; R1-first resistor; R2-second resistor; R3-third resistor; R4-fourth resistor; R5 -fifth resistor; R6-sixth resistor; R7-seventh resistor; R8-eighth resistor; R9-ninth resistor; R10-tenth resistor; R11-eleventh resistor; R12-twelfth resistor; Q1-brake tube; Q2-first transistor; Q3-second transistor; C1-first capacitor; C2-second capacitor; C3-third capacitor; C4-fourth capacitor; D1-first diode; D2-second diode; D3-third diode; D4-fourth diode; D5-fifth diode; U1-first optocoupler isolation device; U2-second optocoupler isolation device; FB1-first output terminal; FB2-second output terminal. DETAILED DESCRIPTION

[0037] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present application are given in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thoroughly and comprehensively understood.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0039] Example:

[0040] This embodiment provides an energy consumption braking circuit. Figures 1 to 7 , which includes but is not limited to a brake pipe Q1 , a brake resistor R, a brake pipe voltage detection unit 101 , a fault signal shielding unit 102 and a processing unit 103 .

[0041] The brake tube Q1 includes but is not limited to transistors such as IGBT or other devices with equivalent or similar functions. The brake tube Q1 includes three electrodes, one of which is a control electrode. When the control electrode is connected to an effective level, the other two electrodes of the brake tube Q1 are turned on (this state is referred to as the brake tube Q1 being turned on or turned on in this application); otherwise, the other two electrodes of the brake tube Q1 are in a cut-off state (this state is referred to as the brake tube Q1 being cut off or cut off in this application). Taking a transistor as an example, its control electrode is the base, and the other two electrodes are the collector and the emitter, respectively. It can be understood that in actual applications, those skilled in the art can determine the actual connection method of each electrode according to the specific device type used by the brake tube Q1 and the functional requirements to be achieved.

[0042] Based on loads with different inertias, the regenerative energy during the deceleration and shutdown process is different, and the power and resistance of the brake resistor R will be different. That is, the brake resistor R needs to be selected and connected according to the actual situation. However, it is very easy to miss, wrongly connect, and short-circuit the two ends of the brake resistor R during the user wiring process, which makes the brake pipe Q1 prone to overcurrent damage. Some detection circuits can only identify abnormalities after the brake pipe Q1 is damaged, and damage cannot be avoided. In order to detect abnormalities during braking in a timely manner, the brake pipe voltage detection unit 101 of this embodiment is configured to control the output level of the first output terminal FB1 according to the collector-emitter voltage drop Vce (that is, the voltage difference between the collector and the emitter) of the brake pipe Q1; wherein, when the brake signal sign indicates braking, the first output terminal FB1 outputs a first level when the brake pipe Q1 is overcurrent, otherwise, it outputs a second level; the first level is one of the high and low levels, and the second level is the other of the high and low levels. It is understandable that when the brake pipe Q1 or the brake resistor R is damaged, such as short circuit or open circuit, the collector-emitter voltage drop Vce of the brake pipe Q1 may also change. In this embodiment, the brake pipe voltage detection unit 101 detects the collector-emitter voltage drop Vce of the brake pipe Q1, and can determine whether the brake pipe Q1 is overcurrent, so that the processing unit 103 can perform the braking stop operation in time, and in some implementation processes, the brake pipe Q1 can be prevented from being damaged.

[0043] For example, in the normal braking process, assuming that the collector-emitter voltage drop Vce of the brake pipe Q1 is V1, the brake pipe voltage detection unit 101 outputs the first level; when overcurrent occurs, it indicates that the brake resistor R is misconnected or short-circuited, then the collector-emitter voltage drop Vce of the brake pipe Q1 must be different from V1, so the level state of the first output terminal FB1 of the brake pipe voltage detection unit 101 will be the second level. The first level and the second level will be determined according to the actual circuit design. In some examples, the first level is a high level and the second level is a low level; in other examples, it can also be the opposite. Taking the optocoupler isolation device as an example, it can control the on and off state of the photosensitive triode at the output end according to whether the voltage at the input end is sufficient to drive the light-emitting diode; when the first output end FB1 is defined at the output end of the optocoupler isolation device, the level state of the first output end FB1 will be determined according to the position of the device subsequently connected to the optocoupler isolation device. For example, if all subsequent devices are set on the grounded output side of the optocoupler isolation device, when the optocoupler isolation device is turned on, the level of its output end will be high; and when the optocoupler isolation device is turned off, the level of its output end will be low. If it is assumed that all subsequent devices are set on the output end of the optocoupler isolation device close to the power supply, the level logic of the optocoupler isolation device will be opposite.

[0044] However, the collector-emitter voltage drop Vce of the brake pipe Q1 may also differ depending on the braking and non-braking states. Figure 2 For example, when the brake pipe Q1 is not turned on, that is, the brake signal sign does not indicate braking, the collector-emitter voltage drop Vce of the brake pipe Q1 is high. At this time, the first output terminal FB1 of the brake pipe voltage detection unit 101 outputs a first level. When the brake pipe Q1 is turned on, the collector-emitter voltage drop Vce of the brake pipe Q1 is very low, and the first output terminal FB1 of the brake pipe voltage detection unit 101 outputs a second level. However, if an overcurrent occurs in the brake pipe Q1 during braking, such as a short circuit in the brake resistor R, the collector-emitter voltage drop Vce of the brake pipe Q1 will remain high, and the first output terminal FB1 of the brake pipe voltage detection unit 101 outputs a first level. It can be seen that in some implementation processes, the above-mentioned brake pipe voltage detection unit 101 does not need to pay attention to the specific voltage value, and can only detect overcurrent based on whether the voltage exceeds a certain specific value, so it can be implemented at a lower cost. However, when an overcurrent occurs in the brake pipe Q1, the level state of the first output terminal FB1 of the brake pipe voltage detection unit 101 is actually the same as the state when not braking, both of which are the first level; this will make the subsequent processing logic complicated and is not conducive to the rapid response of the processing unit 103.

[0045] In order to simplify the signal logic of the first output terminal FB1, the fault signal shielding unit 102 of this embodiment is connected to the first output terminal FB1, and is configured to adjust the level state of the first output terminal FB1 to always be the same as the second level when the brake signal sign does not indicate braking. That is to say, when the brake signal sign does not indicate braking, no matter what the voltage detected by the brake pipe voltage detection unit 101 is, the fault signal shielding unit 102 will force the level state of the first output terminal FB1 to be the same as the second level. The fault signal shielding unit 102 makes the first output terminal FB1 of the brake pipe voltage detection unit 101 present the first level only when overcurrent occurs during braking, and always maintain the second level in other states. Therefore, at any time, as long as the level state of the first output terminal FB1 is detected to be the first level, it means that the energy consumption braking circuit has an abnormality, which simplifies the logic of the signal, so that in some implementation processes, the abnormality prompted by the first output terminal FB1 can be responded to quickly.

[0046] The processing unit 103 in this embodiment is configured to stop braking when receiving the first level. For example, the processing unit 103 can be connected to the first output terminal FB1, and when the level state of the first output terminal FB1 is detected to be the first level, the braking stop operation is triggered. This can timely avoid damage to the brake pipe Q1 caused by overcurrent.

[0047] In some embodiments, the processing unit 103 includes an interrupt input terminal, and the first output terminal FB1 of the brake pipe voltage detection unit 101 is connected to the interrupt input terminal. The processing unit 103 can be a device including but not limited to MCU (Microcontroller Unit), ARM (Advanced RISC Machine), FPGA (Field-Programmable Gate Array) and other devices with processing capabilities. For various processing units 103, the interrupt input terminal is usually pre-defined by the manufacturer. When in use, the first output terminal FB1 can be connected accordingly. The processing unit 103 in this embodiment has an interrupt input terminal, which can execute a preset interrupt event based on the level of the interrupt input terminal, such as triggering an interrupt event at a rising edge or a falling edge; in this embodiment, the interrupt event can be a step of stopping braking. The energy consumption braking circuit of this embodiment simplifies the signal logic of the first output terminal FB1, so that it can be adapted to the usual trigger logic of the interrupt input terminal. By receiving the output result of the first output terminal FB1 of the brake pipe voltage detection unit 101 through the interrupt input terminal, a rapid response to the overcurrent abnormality of the brake pipe Q1 can be achieved.

[0048] In practical applications, devices including but not limited to capacitors are used, and even the line itself has parasitic capacitance, and the transmission of signals has inherent delay. In order to avoid false alarms of the detection results of the brake pipe voltage detection unit 101 due to delay, in some embodiments, the fault signal shielding unit 102 includes a delay subunit. The delay subunit is configured to continue to maintain the level state of the first output terminal FB1 to be the same as the second level during the delay time when the brake signal sign begins to indicate braking; the delay time is greater than the response time of the energy-consuming braking circuit to the brake signal sign; after the delay time, the output level of the first output terminal FB1 is determined according to the collector-emitter voltage drop Vce of the brake pipe Q1. When the brake signal sign changes from a state that does not indicate braking to an indication of braking, due to the delay of the circuit itself, the brake pipe Q1 will not be turned on until a certain time after the brake signal sign changes. The response time of the energy-consuming braking circuit to the brake signal sign is the time from the change of the brake signal sign to the turning on of the brake pipe Q1. The fault signal shielding unit 102 is equivalent to shielding the abnormal detection of the brake pipe voltage detection unit 101 within a certain period of time when the brake signal sign changes, so as to avoid abnormal false alarms at the moment when the brake signal sign changes. In some embodiments, the fault signal shielding unit 102 also includes a non-delay subunit, which is configured to immediately adjust the level state of the first output terminal FB1 to the same as the second level when the brake signal changes from indicating braking to not indicating braking. It is ensured that the fault signal shielding unit 102 can play a role before the brake pipe Q1 is turned off, and in some embodiments, it also avoids abnormal false alarms at the moment when the brake signal sign changes.

[0049] like Figure 3 As shown, in some embodiments, the energy-consuming braking circuit further includes an optocoupler isolation driving unit 104, one of the input ends of which is connected to the braking signal sign, and the output end of which is connected to the control electrode of the brake pipe Q1, so as to output a preset voltage to drive the brake pipe Q1 to turn on when the braking signal sign indicates braking. It is understandable that the optocoupler isolation driving unit 104 can isolate the braking signal sign from the control electrode of the brake pipe Q1, which may include an optocoupler isolation device or a circuit with equivalent functions, which can prevent electrical and noise interference and enhance the reliability of the energy-consuming braking circuit. It is understandable that when the optocoupler isolation device is turned on, a level for driving the brake pipe Q1 can be generated at the output end of the optocoupler isolation driving unit 104.

[0050] In some embodiments, in order to detect abnormal conditions in a non-braking state, the brake pipe voltage detection unit 101 of this embodiment may further include a second output terminal FB2, and the brake pipe voltage detection unit 101 is further configured to control the output level of the second output terminal FB2 according to the collector-emitter voltage drop Vce of the brake pipe Q1; wherein, when the brake signal sign indicates braking, the second output terminal FB2 outputs a third level under normal conditions, and outputs a fourth level when the brake pipe Q1 is disconnected; when the brake signal sign does not indicate braking, the second output terminal FB2 outputs a fourth level under normal conditions, and outputs a third level when the brake pipe Q1 is short-circuited; the third level is one of a high level and a low level, and the fourth level is another of a high level and a low level. In fact, the signal logic of the second output terminal FB2 may be the same as or exactly opposite to the signal logic of the first output terminal FB1 when it is not affected by the fault signal shielding unit 102; but the second output terminal FB2 is not affected by the fault signal shielding unit 102, so when the brake signal sign does not indicate braking, the signal of the second output terminal FB2 will still reflect the collector-emitter voltage drop Vce of the brake pipe Q1. Through the configuration of the second output terminal FB2, it is possible to monitor whether the brake pipe Q1 is damaged and short-circuited in the non-braking state, and to detect abnormalities in time before braking. It can be understood that due to the signal logic of the first output terminal FB1, the overcurrent abnormality in the braking process can be responded to quickly, and the timeliness of processing the abnormality reflected by the second output terminal FB2 is not as high as that of the first output terminal FB1. The second output terminal FB2 can be connected to the ordinary IO (input and output) port of the processing unit 103, and its level state is detected by ordinary detection means.

[0051] In some embodiments, the brake pipe voltage detection unit 101 includes an optocoupler isolator unit 1011, the output end of the optocoupler isolator unit 1011 serves as the second output end FB2, and one of the input ends of the optocoupler isolator unit 1011 is connected between the brake pipe Q1 and the brake resistor R, and at this time, the input end is also connected to the collector or reflector of the brake pipe Q1 to control the level of the output end according to the collector-emitter voltage drop Vce of the brake pipe Q1. The optocoupler isolator unit 1011 can be turned on or off according to the collector-emitter voltage drop Vce of the brake pipe Q1, thereby forming different levels at the output end, and electrical isolation is achieved with good reliability.

[0052] In some embodiments, the brake pipe voltage detection unit 101 includes a first transistor, a control electrode of the first transistor is connected to the second output terminal FB2, and one electrode of the first transistor serves as the first output terminal FB1;

[0053] The fault signal shielding unit 102 includes a second transistor, a control electrode of the second transistor is connected to the braking signal sign, and one of the other two electrodes is connected to the first output terminal FB1; the second transistor is turned on when the braking signal sign does not indicate braking, so as to turn on the circuit where the first output terminal FB1 is located, thereby adjusting the level of the first output terminal FB1 to always be the same as the second level; the second transistor is cut off when the braking signal sign indicates braking, so that the output level of the first output terminal FB1 is determined according to the collector-emitter voltage drop Vce of the brake tube Q1.

[0054] Through two transistors, the brake tube voltage detection unit 101 can form two logically opposite outputs, and the second output terminal FB2 can be unaffected by the fault signal shielding unit 102. Such a design enables the energy-consuming braking circuit to provide a simple logic signal feedback from the first output terminal FB1 in the state of overcurrent during braking, and can also effectively monitor whether the brake tube Q1 is short-circuited by using the second output terminal FB2 in the non-braking state, and does not require a dedicated overcurrent protection chip or device, the cost is not high, and it has a good cost-effectiveness. The first transistor and the second transistor can be triodes or MOS (Metal Oxide Semiconductor Field Effect Transistor) tubes.

[0055] In some embodiments, the fault signal shielding unit 102 further includes an RC delay circuit 1021, which can be used as a delay subunit. The RC delay circuit 1021 includes a first anti-reverse diode and a resistor and a capacitor that cooperate to form a delay. The brake signal sign is connected to the control electrode of the second transistor through the RC delay circuit 1021.

[0056] When the braking signal sign starts to indicate braking, the RC delay circuit 1021 continues to keep the second transistor turned on during the delay time; the delay time is greater than the response time of the energy-consuming braking circuit to the braking signal sign.

[0057] As mentioned above, the delay provided by the RC delay circuit 1021 can avoid abnormal false alarms at the moment when the brake signal sign changes. In some embodiments, the delay subunit can specifically adopt the RC delay circuit 1021, and the delay is formed by the cooperation of resistors and capacitors, and its time constant Γ=RC. Only by adjusting the parameters of the resistors and capacitors, the required delay can be achieved, which is low-cost and stable and reliable. In practical applications, the time constant Γ of the RC delay circuit 1021 is configured according to the specific situation of the circuit.

[0058] In some embodiments, the fault signal shielding unit 102 further includes a non-delay circuit 1022 connected in parallel with the RC delay circuit 1021, the non-delay circuit 1022 is equivalent to a non-delay subunit, and the non-delay circuit 1022 includes a second anti-reverse diode and a resistor; when the braking signal sign is switched to no longer indicate braking, the braking signal sign passes through the loop where the non-delay circuit 1022 is located so that the second transistor is immediately switched to the off state. The non-delay circuit 1022 ensures that when the braking signal sign is switched to no longer indicate braking, the fault signal shielding unit 102 can timely adjust the level state of the first output terminal FB1 to the same as the second level, and can also avoid abnormal false alarms during switching between braking and non-braking.

[0059] This embodiment also provides a driver, which includes the energy consumption braking circuit of the above example. Figure 4 , is an overall principle block diagram of an exemplary driver. The power supply of the driver can be input from the mains VIN, and enter the bus capacitor 106 through the rectification and EMC filtering (Electro Magnetic Compatibility) unit 105. The bus capacitor 106 is connected to the three-phase inverter bridge 107, and finally connected to the load motor 108 through the three-phase inverter bridge 107. The brake pipe Q1 is connected to the bus capacitor 106 and the optical coupling isolation drive unit 104. After detecting that the bus voltage exceeds a predetermined threshold, the processing unit 103 sends a brake signal sign indicating braking. The brake signal sign drives the brake pipe Q1 through the optical coupling isolation drive unit 104. The brake pipe voltage detection unit 101 is connected to the brake pipe Q1 and can send back the detected result to the processing unit 103. The fault signal shielding unit 102 controls the brake pipe voltage detection unit 101 to adjust the level state of the first output terminal FB1 to always be the same as the second level.

[0060] In order to better understand the energy consumption braking circuit of the present application, this embodiment is described in more detail below in conjunction with a specific example. Figure 5 .

[0061] The energy-consuming braking circuit of this example includes a processing unit 103, which includes a main control MCU; the main control MCU sends a braking signal sign, and the braking signal sign is connected to the control pole of the brake pipe Q1 through the optical coupling isolation driving unit 104. When the braking signal sign indicates braking, the brake pipe Q1 is turned on, and the braking resistor R is connected to the braking circuit to perform energy-consuming braking. The brake pipe voltage detection unit 101 includes a detection circuit for detecting the collector-emitter voltage drop Vce of the brake pipe Q1, and an isolation circuit, and the detection result is fed back to the main control MCU through the isolation circuit. The fault signal shielding unit 102 is connected to the isolation circuit, and when the braking signal sign does not indicate braking, the detection result of the brake pipe voltage detection unit 101 is shielded. The fault signal shielding unit 102 can be connected to the braking signal sign, and act according to the braking and non-braking conditions indicated by the braking signal sign. In order to avoid false alarms at the moment of switching between braking and non-braking states, the braking signal sign is transmitted to the fault signal shielding unit 102 through the delay line and non-delay line 1022.

[0062] Based on the basic structure of the above energy-consuming braking circuit, Figure 6 A specific circuit structure diagram is given as an example, wherein the collector of the brake tube Q1 is connected to the brake resistor R, the emitter is grounded, and the other end of the brake resistor R is connected to the bus VDC.

[0063] The brake signal sign is connected to the control electrode of the brake tube Q1 through the optocoupler isolation drive unit 104, and the optocoupler isolation drive unit 104 includes a first optocoupler isolation device U1. In this example, one input end of the first optocoupler isolation device U1 is connected to the 5V power supply VDD, and the other input end is connected to the brake signal sign through the first resistor R1. In this example, the brake signal sign is effective at a low level; when the brake signal sign is at a low level, the first optocoupler isolation device U1 is turned on, and its output end generates a predetermined level signal to drive the brake tube Q1. Exemplarily, the output end of the first optocoupler isolation device U1 is connected to the brake tube Q1 through the second resistor R2, and also includes a third resistor R3 connected in parallel with the second resistor R2 and a first diode D1, the cathode of the first diode D1 is connected to the third resistor R3, and the anode is connected to the control electrode of the brake tube Q1. In addition, a fourth resistor R4 is connected between the control electrode and the emitter of the brake tube Q1, and the control electrode is also connected to the first capacitor C1, and the other end of the first capacitor C1 is grounded.

[0064] The brake tube voltage detection unit 101 includes an optocoupler isolation subunit 1011, which includes a second optocoupler isolation device U2. One input end of the second optocoupler isolation device U2 is connected to the 15V power supply VCC, and the other input end is connected to the collector of the brake tube Q1 through the fifth resistor R5, the second diode D2 and the third diode D3. Since the emitter of the brake tube Q1 is grounded, the voltage at the input end of the second optocoupler isolation device U2 is also the collector-emitter voltage drop Vce of the brake tube Q1. Among them, the anode of the second diode D2 is connected to the fifth resistor R5, the cathode is connected to the anode of the third diode D3, and the cathode of the third diode D3 is connected to the collector of the brake tube Q1; it can be understood that in this example, the protection threshold can be configured by adjusting the resistance value of the fifth resistor R5. In this example, the two input ends of the second optocoupler isolation device U2 are connected through the sixth resistor R6, and the two ends are connected to the second capacitor C2 in a one-to-one correspondence with the two ends of the sixth resistor R6.

[0065] One output end of the second optical coupler isolator U2 is connected to the 5V power supply VDD, and the other output end is used as the second output end FB2 of the brake pipe voltage detection unit 101. When the brake pipe Q1 is turned on, the voltage of the collector of the brake pipe Q1 is low, and the two output ends of the second optical coupler isolator U2 are turned on. At this time, the level state of the second output end FB2 is a high level; when the brake pipe Q1 is turned off, the voltage of the collector of the brake pipe Q1 is high, and the output end of the second optical coupler isolator U2 is not turned on. At this time, the level state of the second output end FB2 is a low level.

[0066] In addition, the brake tube voltage detection unit 101 also includes a first transistor Q2 and a second transistor Q3. The second output terminal FB2 of the brake tube voltage detection unit 101 is connected to the control electrode of the first transistor Q2 through the seventh resistor R7, and the eighth resistor R8 is connected between the control electrode and the emitter of the first transistor Q2, and the emitter is grounded, and the collector is connected to the 5V power supply VDD through the ninth resistor R9. The emitter and collector of the second transistor Q3 are respectively connected to the emitter and collector of the first transistor Q2 in a one-to-one correspondence, and the emitter of the second transistor Q3 is also grounded, and the collector is connected to the 5V power supply VDD through the ninth resistor R9. A third capacitor C3 is connected between the emitter and collector of the first transistor Q2 and the second transistor Q3.

[0067] In this example, the collectors of the first transistor Q2 and the second transistor Q3 serve as the first output terminal FB1 of the brake tube voltage detection unit 101. In practical applications, the first transistor Q2 and the second transistor Q3 may also be two-in-one packaged devices.

[0068] The fault signal shielding unit 102 includes an RC delay circuit 1021 and a non-delay circuit 1022 , which are respectively connected to the control electrode of the second transistor Q3 .

[0069] Wherein, the RC delay circuit 1021 includes a tenth resistor R10, a fourth capacitor C4, an eleventh resistor R11 and a fourth diode D4. The tenth resistor R10 and the fourth capacitor C4 cooperate to cause a delay in the signal change on the RC delay circuit 1021. The anode of the fourth diode D4 is close to the input port of the brake signal sign, and the cathode is close to the control electrode of the second transistor Q3. In this example, one end of the eleventh resistor R11 is connected to the input port of the brake signal sign, and the other end is connected to the anode of the fourth diode D4. The cathode of the fourth diode D4 is connected to the tenth resistor R10 and connected to one end of the fourth capacitor C4; the other end of the fourth capacitor C4 is grounded, and the other end of the tenth resistor R10 is connected to the control electrode of the second transistor Q3. In other examples, the positions of the fourth diode D4 and the eleventh resistor R11 can also be interchanged.

[0070] The non-delay circuit 1022 includes a twelfth resistor R12 and a fifth diode D5, wherein the anode of the fifth diode D5 is connected to the input port of the brake signal sign, the cathode is connected to the twelfth resistor R12, and the other end of the twelfth resistor R12 is connected to the control electrode of the second transistor Q3.

[0071] As an alternative, in other examples, the fourth diode D4 and the fifth diode D5 may also be double-in-one switching diodes with a common anode.

[0072] At the moment when the brake signal sign changes from high level to low level, due to the effect of the RC delay circuit 1021, the control electrode of the second transistor Q3 is still in a high level state within a certain delay, that is, the second transistor Q3 is turned on, so that the level of the first output terminal FB1 is kept low. The delay caused by the RC delay circuit 1021 is greater than the time for the brake signal sign to be transmitted to the brake tube Q1 through the optical coupling isolation driving unit 104, thereby avoiding the false alarm caused by the brake tube voltage detection unit 101 changing its detection state when the brake tube Q1 is not turned on.

[0073] At the moment when the brake signal sign changes from low level to high level, due to the existence of the non-delay circuit 1022, the high level voltage can be applied to the control electrode of the second transistor Q3 through the non-delay circuit 1022 without delay, thereby timely maintaining the level of the first output terminal FB1 in a low state.

[0074] In this example, the first output terminal FB1 of the brake pipe voltage detection unit 101 is connected to the high-speed interrupt pin of the processing unit 103. The processing unit 103 is configured to immediately stop braking once the first output terminal FB1 of the brake pipe voltage detection unit 101 is at a high level, thereby protecting the brake pipe Q1 from overcurrent damage.

[0075] See Table 1 below for some of the signal logic of the above circuit:

[0076]

[0077] It is understandable that the processing unit 103 can determine whether the dynamic braking circuit is abnormal only according to the level state of the first output terminal FB1 and the second output terminal FB2. The state shown in Table 1 is when the brake pipe Q1 is normal. If the level of the second output terminal FB2 is different from the state in Table 1, the brake pipe Q1 may be damaged.

[0078] In the non-braking state, it is normal when the second output terminal FB2 is at a low level, and it is abnormal when it is at a high level. The processing unit 103 can directly determine whether the current state is non-braking or braking in the software. If in the non-braking state, the second output terminal FB2 is at a high level, it indicates that the brake tube Q1 is damaged and a short circuit occurs between the collector and the emitter. The processing unit 103 can issue an alarm based on this to prompt the user to handle the abnormality.

[0079] In the braking state, it is normal when the second output terminal FB2 is at a high level, and it is abnormal when it is at a low level. The processing unit 103 can directly determine whether the current state is a non-braking state or a braking state in the software. If in the braking state, the second output terminal FB2 is at a low level, it indicates that the brake tube Q1 is damaged and an open circuit occurs between the collector and the emitter. The processing unit 103 can issue an alarm based on this to prompt the user to handle the abnormality.

[0080] like Figure 7 The example shows a curve of the relationship between the collector and emitter voltage (i.e., the collector-emitter voltage drop Vce) of a brake tube Q1 (example is a 75A / 1200V specification PIM). When the brake tube Q1 is overcurrent due to a short circuit of the brake resistor R, as the collector current Ic of the brake tube Q1 rises rapidly in an instant, the collector-emitter voltage drop Vce of the brake tube Q1 also rises rapidly. In most cases, when the collector current Ic is approximately equal to twice the rated current of the specification, the collector-emitter voltage drop Vce is approximately 2.5 to 2.8V. Based on this, the short-circuit overcurrent protection function can be realized by detecting its collector-emitter voltage drop Vce when the brake tube Q1 is in the on state. In this example, when the voltage of the collector of the brake tube Q1 increases, the level of the first output terminal FB1 becomes a high level state, and the processing unit 103 immediately takes measures to stop braking, such as blocking the brake signal sign.

[0081] The above-mentioned energy-consuming braking circuit does not need to use chips, optocouplers and other devices with special overcurrent protection functions, and can obtain the required detection results based on ordinary optocoupler isolation devices and transistors. In addition, for overcurrent anomalies, the processing unit 103 can take a quick response to avoid damage to the brake pipe Q1; in addition, even if the brake pipe Q1 is short-circuited, it can be detected and alarmed in advance, and there is no need to find the problem after braking. It can be seen that the energy-consuming braking circuit of the example has a high cost-effectiveness.

[0082] It should be noted that the above examples all take the braking signal sign as being effective at a low level (i.e., indicating braking when at a low level), and the transistor is of NPN type; in actual applications, the braking signal sign can also be designed to be effective at a high level, and the transistor can be of PNP type. It is understandable that the overall design of the energy-consuming braking circuit needs to be adaptively adjusted for changes in the effective level. Based on the design ideas provided in this embodiment, those skilled in the art can easily perform the above conventional transformations. In addition, the high level and low level referred to in this application only represent two recognizable logical states, and this application does not limit the specific numerical range of the high level and the low level. It is understandable that the circuit functions mentioned in this embodiment can all be implemented through hardware, or the combination of hardware and existing software, and each circuit unit can be a combination of one or more electronic devices with corresponding functions, or a chip, or an integrated circuit.

[0083] It should be understood that the application of the present invention is not limited to the above examples. For ordinary technicians in this field, improvements or changes can be made according to the above description. All these improvements and changes should fall within the scope of protection of the claims attached to the present invention.

Claims

1. An energy-consuming braking circuit, characterized in that: include: A brake pipe, a control electrode of which is connected to a brake signal and is turned on to perform energy-consuming braking when the brake signal indicates braking; A brake resistor connected to one end of the brake pipe, when energy-consuming braking is performed, the brake pipe is turned on, and the brake resistor is connected to the brake circuit to consume the energy generated by braking; A brake pipe voltage detection unit, comprising a first output terminal; the brake pipe voltage detection unit is configured to control an output level of the first output terminal according to a collector-emitter voltage drop of the brake pipe; wherein the first output terminal outputs a first level when the brake signal indicates braking and the brake pipe is overcurrent, otherwise, outputs a second level; the first level is one of a high level and a low level, and the second level is another of the high level and the low level; a fault signal shielding unit connected to the first output terminal, configured to adjust the level state of the first output terminal to always be the same as the second level when the braking signal does not indicate braking; A processing unit connected to the first output terminal.

2. The dynamic braking circuit according to claim 1, characterized in that: The processing unit comprises an interrupt input terminal, and the first output terminal is connected to the interrupt input terminal.

3. The dynamic braking circuit according to claim 1, characterized in that: The fault signal shielding unit includes a delay subunit and a non-delay subunit; The delay subunit is configured to continue to maintain the level state of the first output terminal to be the same as the second level within a delay time when the brake signal starts to indicate braking; the delay time is greater than the response time of the dynamic braking circuit to the brake signal; After the delay time, the output level of the first output terminal is determined according to the collector-emitter voltage drop of the brake pipe; The non-delay subunit is configured to immediately adjust the level state of the first output terminal to be the same as the second level when the braking signal changes from indicating braking to not indicating braking.

4. The dynamic braking circuit according to claim 1, characterized in that: The energy-consuming braking circuit also includes an optocoupler isolation driving unit, one of the input ends of which is connected to the braking signal, and the output end of which is connected to the control electrode of the brake pipe, so as to output a preset voltage to drive the brake pipe to conduct when the braking signal indicates braking.

5. The dynamic braking circuit according to any one of claims 1 to 4, characterized in that: The brake pipe voltage detection unit further includes a second output terminal, and the brake pipe voltage detection unit is further configured to control an output level of the second output terminal according to a collector-emitter voltage drop of the brake pipe; wherein the second output terminal outputs a third level under normal circumstances when the brake signal indicates braking, and outputs a fourth level when the brake pipe is disconnected; when the brake signal does not indicate braking, the second output terminal outputs a fourth level under normal circumstances, and outputs the third level when the brake pipe is short-circuited; the third level is one of a high level and a low level, and the fourth level is another of the high level and the low level; The processing unit is also connected to the second output end, and the first output end and the second output end are connected to different ports of the processing unit.

6. The dynamic braking circuit according to claim 5, characterized in that: The brake pipe voltage detection unit includes an optocoupler isolator unit, the output end of the optocoupler isolator unit serves as the second output end, and one of the input ends of the optocoupler isolator unit is connected between the brake pipe and the brake resistor to control the level of the output end according to the collector-emitter voltage drop of the brake pipe.

7. The dynamic braking circuit according to claim 6, characterized in that: The brake pipe voltage detection unit comprises a first transistor, a control electrode of the first transistor is connected to the second output end, and one electrode of the first transistor serves as the first output end; The fault signal shielding unit includes a second transistor, a control electrode of the second transistor is connected to the braking signal, and one of the other two electrodes is connected to the first output end; the second transistor is turned on when the braking signal does not indicate braking, so as to turn on the circuit where the first output end is located, thereby adjusting the level of the first output end to always be the same as the second level; the second transistor is cut off when the braking signal indicates braking, so that the output level of the first output end is determined according to the collector-emitter voltage drop of the brake tube.

8. The dynamic braking circuit according to claim 7, characterized in that: The fault signal shielding unit further includes an RC delay circuit, the RC delay circuit includes a first anti-reverse diode and a resistor and a capacitor that cooperate to form a delay, and the brake signal is connected to the control electrode of the second transistor through the RC delay circuit; When the braking signal starts to indicate braking, the RC delay circuit continues to keep the second transistor turned on during the delay time; the delay time is greater than the response time of the energy-consuming braking circuit to the braking signal.

9. The dynamic braking circuit according to claim 8, characterized in that: The fault signal shielding unit further includes a non-delay circuit connected in parallel with the RC delay circuit, wherein the non-delay circuit includes a second anti-reverse diode and a resistor; When the braking signal is switched to no longer indicate braking, the braking signal passes through the loop where the non-delay circuit is located so that the second transistor is immediately switched to a cut-off state.

10. A driver, characterized in that: It comprises the energy-consuming braking circuit as described in any one of claims 1 to 9.

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