Control device and control system for an elevator

Abstract

Provided is a control device for an elevator, including: a capacitor circuit for increasing braking torque of a three-phase motor when each phase terminal of the three-phase motor is connected; a switching component for switching each phase terminal of the three-phase motor between a drive circuit and the capacitor circuit; and a detection component, in a case where each phase terminal of the three-phase motor is switched by the switching component to the capacitor circuit, in response to receiving a test enable signal, sequentially applying an excitation signal to one or more of a plurality of LC oscillation circuits in a braking circuit constituted by the capacitor circuit and each phase coil of the three-phase motor and detecting whether the LC oscillation circuit to which the excitation signal is applied generates LC oscillation, in a case where it is detected that each of the plurality of LC oscillation circuits generates LC oscillation, outputting a test pass signal to indicate that there is no open circuit in the braking circuit.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a control device for an elevator and a control system including the control device. BACKGROUND

[0002] In some use scenarios of an elevator, a situation of coasting down of the elevator can occur. In order to limit the speed of the coasting down of the elevator, a feasible method is to short-circuit the phase terminals of a motor serving as a hoisting machine of the elevator to form a braking circuit to generate a braking torque for limiting the speed of the coasting down of the elevator when the motor is stopped from being powered. Therefore, the normal operation of the braking circuit is crucial to the safety of the elevator. However, due to the dark and humid use environment of the elevator, there is a risk of open circuit of the braking circuit, for example, the wires are bitten off by a mouse. If there is an open circuit inside the braking circuit, the function of limiting the coasting down of the elevator will no longer exist. SUMMARY

[0003] In view of the above, one aspect of the present disclosure provides a control device for an elevator, comprising: a capacitor circuit configured to communicate the phase terminals of a three-phase motor when connected to the phase terminals to increase the braking torque of the three-phase motor; a switching component configured to switch the phase terminals of the three-phase motor between the drive circuit and the capacitor circuit; and a detection component, in the case that the phase terminals of the three-phase motor are switched to the capacitor circuit by the switching component, in response to receiving a test enable signal, sequentially applies an excitation signal to one or more of a plurality of LC oscillation circuits in a braking circuit composed of the capacitor circuit and the phase coils of the three-phase motor and detects whether the LC oscillation circuit to which the excitation signal is applied generates LC oscillation, and in the case that each of the plurality of LC oscillation circuits generates LC oscillation, outputs a test pass signal to indicate that there is no open circuit in the braking circuit.

[0004] Optionally, the detection component does not output any signal in the case that it is detected that at least one of the plurality of LC oscillation circuits does not generate LC oscillation.

[0005] Optionally, the detection component does not generate the excitation signal any more once it is detected that one of the plurality of LC oscillation circuits does not generate LC oscillation.

[0006] Optionally, the detection component outputs a test failure signal in the case that it is detected that at least one of the plurality of LC oscillation circuits does not generate LC oscillation, the test failure signal comprising information indicating in which of the plurality of LC oscillation circuits no LC oscillation is detected.

[0007] Optionally, the detection component comprises: a microcontroller, which generates the excitation signal for the first time to be applied to one of the plurality of LC oscillation circuits in response to receiving the test permission signal; and a detection circuit, which is connected with each of the plurality of LC oscillation circuits to detect whether LC oscillation is generated in the LC oscillation circuit to which the excitation signal is applied, and outputs a detection signal indicating whether the LC oscillation is detected to the microcontroller, wherein the microcontroller generates the excitation signal again to be applied to the next LC oscillation circuit in the plurality of LC oscillation circuits after receiving the detection signal, and the microcontroller outputs the test pass signal in the case that each of a plurality of detection signals received respectively corresponding to the plurality of LC oscillation circuits indicates that the LC oscillation is detected.

[0008] Optionally, the excitation signal is a pulse width modulation signal, and the detection component further comprises a conversion circuit coupled between the microcontroller and the brake circuit, for converting the pulse width modulation signal into a voltage signal or a current signal suitable for being applied to the LC oscillation circuit in the brake circuit.

[0009] Optionally, the detection circuit comprises an operational amplifier and a comparator.

[0010] Optionally, the capacitor circuit comprises capacitors connected in a star or delta connection.

[0011] Optionally, the control device further comprises a power supply component for supplying power to the control device.

[0012] Another aspect of the present disclosure provides a control system for an elevator, comprising the control device of any one of the preceding aspects and a main controller of the elevator, the main controller being configured to send the test permission signal to the control device in the case that the elevator is idle.

[0013] Optionally, the main controller sends the test permission signal to the control device again in response to not receiving the test pass signal within a predetermined threshold period of time, and deactivates the elevator in response to not receiving the test pass signal for the second time within a predetermined threshold period of time.

[0014] The control device and the control system according to the embodiments of the present disclosure further implement the function of detecting whether the brake circuit for limiting the speed of the elevator in overrun is open on the basis of the brake circuit configured to limit the speed of the elevator in overrun, thereby providing stronger guarantee for the safety of the elevator in use. BRIEF DESCRIPTION OF DRAWINGS

[0015] The aspects, features and advantages of the present disclosure will become more apparent and easily understood from the following description of the embodiments of the present disclosure, taken in conjunction with the accompanying drawings, in which:

[0016] Figure 1 A schematic use scenario of a control device according to embodiments of the disclosure is shown;

[0017] Figure 2A and Figure 2B A working principle of a detection component according to embodiments of the disclosure is shown;

[0018] Figure 3 A schematic block diagram of a detection component according to embodiments of the disclosure is shown;

[0019] Figure 4 A schematic block diagram of a control system according to embodiments of the disclosure is shown; and

[0020] Figure 5 Examples of a test enable signal and a test pass signal are shown. DETAILED DESCRIPTION

[0021] The present disclosure will be described in detail below with reference to the accompanying drawings. However, the present disclosure is not limited to the embodiments described herein, which can be implemented in many different forms. The described embodiments are merely for making the present disclosure thorough and complete, and for fully conveying the ideas of the present disclosure to those skilled in the art. The features of the described various embodiments can be combined or replaced with each other, unless explicitly excluded or should be excluded according to the context.

[0022] Unless otherwise defined, technical terms or scientific terms used in the present disclosure should be understood as the common meanings to those skilled in the art of the present disclosure. The terms “first”, “second” and similar words used in the present disclosure do not represent any order, number or importance, but are only used to distinguish different constituent parts.

[0023] In the drawings, the same reference numerals indicate the same or similar structural or functional components, and repetitive descriptions thereof will be omitted in the following description.

[0024] Figure 1 A schematic use scenario of a control device according to embodiments of the disclosure is shown.

[0025] As Figure 1As shown, the three-phase motor M serves as a hoisting machine of an elevator, and drives the traction sheave 2 to rotate when energized. The traction sheave 2 is suspended by a traction rope at both ends to hang a car 4 and a counterweight 5 of the elevator. The counterweight 5 has a mass smaller than that of the car 4, for example, half of the mass of the car 4. The brake 3 mainly includes an electromagnet, brake shoes, a hand brake, and the like (not shown in the figure). In the case where the electromagnet is energized, the brake shoes release the traction sheave 2, so that the traction sheave 2 can be driven to rotate by the three-phase motor M. In the case where the electromagnet is de-energized, the brake shoes grip the traction sheave 2, so that the traction sheave 2 cannot rotate. The hand brake of the brake 3 is used to release the brake shoes from the traction sheave 2 when pulled down by a person. The drive circuit 6 is used to supply power to the three-phase motor M, and can include a three-phase AC power source 61, a main contactor 62, a frequency converter 63, and the like.

[0026] The control device 1 according to the embodiment of the present disclosure includes a capacitor circuit 11, a switching member 12, and a detection member 13.

[0027] The principle of limiting the speed of the elevator in free fall by the capacitor circuit 11 and the switching member 12 will be introduced first.

[0028] The capacitor circuit 11 is used to connect the phase terminals u, v, and w of the three-phase motor M to each other to increase the braking torque of the three-phase motor M when all the phase terminals of the three-phase motor M are connected. The capacitor circuit 11 includes capacitors connected in a star or delta connection. Figure 1 For example, the capacitor circuit includes a first capacitor C1, a second capacitor C2, and a third capacitor C3 connected in a delta connection, but the present disclosure is not limited thereto. Each of the first to third capacitors C1 to C3 can also include various modifications, for example, a plurality of capacitors connected in parallel, a plurality of capacitors connected in series, or a certain number of capacitors and inductors connected in series, and the like.

[0029] The switching member 12 is used to switch the phase terminals u, v, and w of the three-phase motor M between the drive circuit 6 and the capacitor circuit 11. For example, the switching member 12 includes a first group of switches S1-1, S1-2, and S1-3 and a second group of switches S2-1, S2-2, and S2-3 linked together. When the first group of switches S1-1, S1-2, and S1-3 in the switching member 12 are closed while the second group of switches S2-1, S2-2, and S2-3 are opened, the phase terminals of the three-phase motor M are connected to the drive circuit 6 and disconnected from the capacitor circuit 11. When the first group of switches S1-1, S1-2, and S1-3 in the switching member 12 are opened while the second group of switches S2-1, S2-2, and S2-3 are closed, the phase terminals of the three-phase motor M are connected to the capacitor circuit 11 and disconnected from the drive circuit 6. The present disclosure does not limit the structure type of each switch S1-1 to S1-3 and S2-1 to S2-3, for example, they can be single-pole single-throw switches, single-pole double-throw switches, contactors, relays, solid-state switches, and the like.

[0030] When the elevator needs to start running, the switching component 12 closes the first group of switches S1-1, S1-2 and S1-3 while opening the second group of switches S2-1, S2-2 and S2-3, and the phase terminals of the three-phase motor M are switched to be connected with the phase terminals of the driving circuit 6. The driving circuit 6 thereby provides three-phase current to the three-phase motor M, so that the three-phase motor M rotates at a certain rotational speed (for example, the rated rotational speed), and in turn drives the traction sheave 2 to rotate, so as to realize the running of the elevator.

[0031] When the elevator needs to stop running, the switching component 12 opens the first group of switches S1-1, S1-2 and S1-3 while closing the second group of switches S2-1, S2-2 and S2-3, and the phase terminals of the three-phase motor M are switched to be connected with the phase terminals of the capacitor circuit 11. The driving circuit 6 thereby stops providing three-phase current to the three-phase motor M. The first to third capacitors C1 to C3 in the capacitor circuit 11 and the phase windings in the three-phase motor M constitute a braking circuit. At this time, if the brake shoes in the brake 3 can tightly hold the traction sheave 2, the three-phase motor M stops rotating, and no current flows in the braking circuit, which has no effect. On the contrary, if the brake shoes in the brake 3 cannot tightly hold the traction sheave 2 due to aging, wear, etc., or the hand brake of the brake 3 is artificially pulled down (for example, when the elevator fails and needs to be rescued), so that the traction sheave 2 is released, the three-phase motor M will forcibly rotate under the action of the unbalanced torque caused by the mass difference between the car 4 and the counterweight 5 and work as a generator to generate an induced voltage in its interior. The induced voltage causes current to flow in the braking circuit, and in turn generates a braking torque. The braking torque counteracts the unbalanced torque caused by the mass difference between the car 4 and the counterweight 5, thereby limiting the coasting speed of the elevator within a specified range.

[0032] The principles of detecting whether an open circuit exists in the braking circuit by the detection component 13 will be described below in connection with Figure 1 , Figure 2A and 2B .

[0033] Figure 2A and Figure 2B show the working principles of the detection component according to the embodiments of the present disclosure. Among them Figure 2A and Figure 2B respectively show two equivalent circuits of the braking circuit.

[0034] Reference is made to Figure 2Awherein an equivalent circuit of the braking circuit is shown when the capacitors in the capacitor circuit 11 are connected in a delta connection. As shown in the figure, the braking circuit includes three LC oscillation circuits. A first LC oscillation circuit is constituted by the first capacitor Cl, a u-phase coil Lu and a v-phase coil Lv of the three-phase motor M. A second LC oscillation circuit is constituted by the second capacitor C2, the v-phase coil Lv and a w-phase coil Lw of the three-phase motor M. A third LC oscillation circuit is constituted by the third capacitor C3, the u-phase coil Lu and the w-phase coil Lw of the three-phase motor M.

[0035] Referring to Figure 2B wherein an equivalent circuit of the braking circuit is shown when the capacitors in the capacitor circuit 11 are connected in a star connection. As shown in the figure, the braking circuit also includes three LC oscillation circuits. A fourth LC oscillation circuit is constituted by the first capacitor Cl, the second capacitor C2, the u-phase coil Lu and the v-phase coil Lv of the three-phase motor M. A fifth LC oscillation circuit is constituted by the second capacitor C2, the third capacitor C3, the v-phase coil Lv and the w-phase coil Lw of the three-phase motor M. A sixth LC oscillation circuit is constituted by the first capacitor Cl, the third capacitor C3, the u-phase coil Lu and the w-phase coil Lw of the three-phase motor M.

[0036] Only by way of example Figure 2A the principle of the detection section 13 detecting whether an open circuit exists in the braking circuit will be explained.

[0037] Referring to Figure 2A In response to receiving the test enable signal Test_ENABLE, the detection section 13 applies the excitation signal Test_IN to one or more of the first to third LC oscillation circuits in turn, and detects whether LC oscillation is generated in the LC oscillation circuit to which the excitation signal Test_IN is applied. In the case where the excitation signal is applied to each of the LC oscillation circuits and LC oscillation is detected in each of the LC oscillation circuits, a test pass signal Test_PASS is output.

[0038] For example, as shown in the figure, upon receiving the test enable signal Test_ENABLE, the detection section 13 first applies an excitation signal Test_IN to a first LC oscillation circuit composed of the first capacitor Cl, the u-phase coil Lu, and the v-phase coil Lv of the three-phase motor M, which forms a voltage between the terminal pl and the terminal p2. The excitation signal Test_IN can be directly a voltage signal suitable for being applied between the terminal pl and the terminal p2, or can be another signal such as a pulse width modulation signal that can be converted into a voltage signal suitable for being applied between the terminal pl and the terminal p2. The pulse width modulation signal can be converted into a voltage signal suitable for being applied between the terminal pl and the terminal p2 by a conversion circuit composed of components such as a solid-state switch, a potentiometer, a relay, or the like. Also, the present disclosure is not limited to this, and another signal that can cause the LC oscillation circuit to oscillate or that can cause the LC oscillation circuit to oscillate after being appropriately converted and adjusted can be used as the excitation signal Test_IN. If there is no open circuit in the first LC oscillation circuit, as soon as a voltage is formed between the terminal pl and the terminal p2, oscillation occurs in the first LC oscillation circuit, and this oscillation can be detected by the detection section 13. If there is an open circuit in the first LC oscillation circuit, even if a voltage is formed between the terminal pl and the terminal p2, oscillation does not occur in the first LC oscillation circuit.

[0039] After detecting the first LC oscillation circuit, similarly, the detection section 13 applies an excitation signal Test_IN to a second LC oscillation circuit composed of the second capacitor C2, the v-phase coil Lv, and the w-phase coil Lw of the three-phase motor M, which forms a voltage between the terminal p2 and the terminal p3. If there is no open circuit in the second LC oscillation circuit, the second LC oscillation circuit will oscillate and be detected by the detection section 13, and if there is an open circuit, the second LC oscillation circuit will not oscillate.

[0040] After detecting the second LC oscillation circuit, similarly, the detection section 13 applies an excitation signal Test_IN to a third LC oscillation circuit composed of the third capacitor C3, the u-phase coil Lu, and the w-phase coil Lw of the three-phase motor M, and detects oscillation thereof in the case where there is no open circuit in the third LC oscillation circuit.

[0041] In the case where oscillation of the LC is detected in each of the first to third LC oscillation circuits, the detection section 13 outputs a test pass signal Test_PASS.

[0042] The test in the above description allows the signal Test_ENABLE to be received from an external device, which can be a main controller of the elevator or other device capable of detecting whether the elevator is idle or receiving an indication associated with whether the elevator is idle. The test in the above description can be, for example, an audible or visual signal that can be heard or seen by the elevator administrator and understood as a test pass, or a signal output to the external device for the external device to emit an audible or visual signal that can be heard or seen by the elevator administrator and understood as a test pass.

[0043] In one example, the detection component 13 applies the excitation signal to the first to third LC oscillation circuits in turn, and does not output any signal in the case where LC oscillation is not detected in at least one of the first to third LC oscillation circuits. In this case, an external device such as a main controller of the elevator can be set to judge a test failure according to not receiving the test pass signal Test_PASS within a predetermined threshold period of time, after which an audible or visual signal that can be heard or seen by the elevator administrator and understood as a test failure is emitted by the external device. Further, in this example, in order to reduce energy consumption and save resources, the detection component 13 can also be configured to, once it detects that one of the plurality of LC oscillation circuits has not generated LC oscillation, no longer generate an excitation signal to apply the excitation signal to the next oscillation circuit, nor output any signal. For example, the detection component 13 detects that the first LC oscillation circuit has not generated oscillation during detection thereof, and the detection component 13 no longer generates an excitation signal to detect the second LC oscillation circuit, nor outputs any signal.

[0044] In another example, the elevator administrator wishes to accurately locate the circuit portion of the brake circuit to be repaired, the detection component 13 can apply the excitation signal to the first to third LC oscillation circuits in turn, and output a test failure signal Test_FAIL in the case where LC oscillation is not detected in at least one of the first to third LC oscillation circuits, and include information indicating in which LC oscillation circuits LC oscillation was not detected in the test failure signal Test_FAIL. For example, the detection component 13 detects oscillation in the first LC oscillation circuit, but does not detect oscillation in the second and third LC oscillation circuits, and can include information reflecting that oscillation was not detected in the second and third LC oscillation circuits in the test failure signal Test_FAIL. The elevator administrator can judge from the test failure signal that there is an open circuit in the intersection portion of the second and third LC oscillation circuits.

[0045] Thus, the control device according to the embodiments of the present disclosure not only limits the coasting speed of the elevator by configuring the above brake circuit, but also detects whether there is an open circuit in the brake circuit by the detection component, providing additional protection for the function of limiting the coasting speed.

[0046] It should be understood that Figure 2A and Figure 2B The number and position of ports p1-p3 shown in FIGS. 1, 2, 3, 4, 5, and 6 are not a limitation of the present disclosure. For example, although Figure 2A and Figure 2B The first to sixth LC oscillation circuits are shown as LC parallel oscillation circuits in FIGS. 1, 2, 3, 4, 5, and 6, but the first to sixth LC oscillation circuits can also be considered as LC series oscillation circuits. Voltage signals are used as the start-up signals of the first to third LC oscillation circuits in the above description, but current signals can also be applied as the start-up signals via resistors by, for example, adding resistors in the first to sixth LC oscillation circuits. Therefore, different numbers and positions of ports can be had in consideration of different configurations and different start-up manners of the LC oscillation circuits. The present disclosure does not exhaustively list them for the sake of simplicity.

[0047] In addition, the control device 1 can also include a power supply component shown in the figures to supply power to the capacitor circuit 11, the switching component 12, and the detection component 13. The power supply component can be a component coupled with the driving circuit 6 to perform power supply using the power supply from the driving circuit 6, or a component to perform power supply using a power supply independent of the driving circuit 6.

[0048] Figure 3 A schematic block diagram of the detection component according to an embodiment of the present disclosure is shown. The components shown in the dashed box are optional.

[0049] Referring to Figure 3 The detection component 13 includes a microcontroller 131 and a detection circuit 132, and optionally, a conversion circuit 133.

[0050] The microcontroller 131 can be an integrated circuit containing a central processing unit, memory, input / output ports, and other peripherals, or other devices or apparatuses having functions such as processing data, controlling input / output, implementing logical operations, providing timing and counting, and being able to perform computing tasks such as analog and digital signal processing. The microcontroller 131 can be programmed using assembly languages such as X86, ARM, MIPS, PowerPC and / or high-level programming languages such as C, Python, JavaScript, Ruby to implement the functions described in the present disclosure.

[0051] For example, as shown in the figure, the microcontroller 131 generates and applies an excitation signal Test IN to a first LC oscillation circuit composed of a first capacitor CI, a u-phase inductance Lu, and a v-phase inductance Lv. As mentioned previously, the excitation signal Test IN can be a voltage signal directly applied between the ports pi and p2, or another signal such as a pulse width modulation signal that can be converted by the conversion circuit 133 into a voltage signal suitable for application between the ports pi and p2. Alternatively, the conversion circuit 133 can be connected between the microcontroller 131 and the brake circuit for converting, for example, the excitation signal Test IN generated by the microcontroller 131 into a voltage signal suitable for application between the ports pi and p2.

[0052] The detection circuit 132 can be a circuit capable of identifying an oscillation voltage or an oscillation current in the LC oscillation circuit, including operational amplifiers, comparators, and other electrical components (e.g., resistors, capacitors, transistors, etc.). Since detectors and detection principles are well known to those skilled in the art, the present disclosure does not limit the specific configuration of the detection circuit 132.

[0053] For example, as shown in the figure, the detection circuit 132 is coupled between the microcontroller 131 and the brake circuit or between the conversion circuit 133 and the brake circuit via the ports di, d2, d3. If the first LC oscillation circuit does not have an open circuit, the detection circuit 132 will detect an oscillation (e.g., an oscillation voltage or an oscillation current) in the first LC oscillation circuit via the port di and the port d2. The detection circuit 132 outputs a detection signal Out uv to the microcontroller 131 that can indicate whether an oscillation was detected in the first LC oscillation circuit. The microcontroller 131 determines whether an LC oscillation was generated in the first LC oscillation circuit based on the detection signal Out uv.

[0054] After the microcontroller 131 receives the detection signal Out uv corresponding to the first LC oscillation circuit, it again generates an excitation signal Test IN to apply a voltage between the second port p2 and the third port p3. Similarly, if the second LC oscillation circuit does not have an open circuit, the detection circuit 132 will detect an oscillation in the second LC oscillation circuit via the port d2 and the port d3. The detection circuit 132 outputs a detection signal Out vw to the microcontroller 131 that can indicate whether an oscillation was detected in the second LC oscillation circuit. The microcontroller 131 determines whether an LC oscillation was generated in the second LC oscillation circuit based on the detection signal Out vw.

[0055] After the microcontroller 131 receives the detection signal Out_uw corresponding to the second LC oscillation circuit, the microcontroller 131 generates the excitation signal Test_IN again to cause the voltage to be applied between the port pl and the port p3. Similarly, if there is no open circuit in the third LC oscillation circuit, the detection circuit 132 detects the oscillation in the third LC oscillation circuit via the port dl and the port d3. The detection circuit 132 outputs the detection signal Out_uw to the microcontroller 131, which indicates whether the oscillation is detected in the third LC oscillation circuit. The microcontroller 131 determines whether the LC oscillation is generated in the third LC oscillation circuit based on the detection signal Out_uw.

[0056] The microcontroller 131 outputs the test pass signal Test_PASS when all of the three detection signals Out_uv, Out_vw, and Out_uw corresponding to the first to third LC oscillation circuits indicate that the LC oscillation is generated.

[0057] In one example, the microcontroller 131 outputs the test fail signal Test_FAIL when the excitation signal is applied to the first to third LC oscillation circuits in sequence and at least one of the three detection signals Out_uv, Out_vw, and Out_uw indicates that the oscillation is not generated. The test fail signal Test_FAIL can include information indicating which LC oscillation circuit or circuits in which the oscillation is not detected. For example, the microcontroller 131 determines that the oscillation is detected in the first LC oscillation circuit and the oscillation is not detected in the second and third LC oscillation circuits based on the detection signals Out_uv, Out_vw, and Out_uw, and the microcontroller 131 can generate the test fail signal Test_FAIL including information reflecting that the oscillation is not detected in the second and third LC oscillation circuits. The elevator manager can determine that there is an open circuit in the intersection portion of the second and third LC oscillation circuits based on the test fail signal.

[0058] In another example, the elevator administrator does not require to precisely locate the portion of the brake circuit to be repaired, the microcontroller 131 can be programmed to stop working, not output any signal, in the case that at least one of the three detection signals Out_uv, Out_vw and Out_uw indicates that no oscillation is generated after sequentially applying the excitation signal to the first to third LC oscillation circuits. In this case, an external device connected to the microcontroller 131, such as an elevator main controller, can judge the test to be failed according to that no test pass signal Test_PASS is received within a predetermined threshold period of time, and then issue an audible or visual signal that can be heard or seen by the elevator administrator and understood as a test failure. Further, to save energy and resources, in this example, the microcontroller 131 can be further programmed to stop working, not generate the excitation signal any more and not output any signal once the detection signal indicating that no oscillation is generated in the corresponding LC oscillation circuit is detected. For example, the microcontroller 131 does not generate the excitation signal to detect the second LC oscillation circuit and does not output any signal any more once the detection Out_uv indicating that no LC oscillation is generated in the first LC oscillation circuit is received.

[0059] Thus, the detection components in the control device 1 are configured by the microcontroller 131 and the detection circuit 132, so that the control device has simple structure, low cost and strong practicability.

[0060] The control device 1 according to the embodiments of the present disclosure is introduced above, and the control system containing the control device 1 is introduced below. Figure 4 Figure 5 The control system containing the control device 1 is introduced below.

[0061] Figure 4 A schematic block diagram of the control system for the elevator according to the embodiments of the present disclosure is shown. Figure 5 Examples of the test permission signal and the test pass signal are shown.

[0062] Referring to Figure 4 The control system 40 according to the embodiments of the present disclosure includes the main controller 41 of the elevator and the aforementioned control device 1. The elevator main controller 41 here refers to the device responsible for monitoring the running state of the elevator, controlling the start and stop of the elevator, direction conversion and the opening and closing of the car door. The main controller 41 can include, for example, a central processing unit to control the running state of the elevator and monitor various parameters of the elevator, an integrated circuit to perform the transmission and conversion of signals between the central processing unit, relays, frequency converters and the like. Figure 1 The main contactor 62 and the frequency converter 63 in the main controller 41 can be part of the main controller 41.

[0063] ​In the embodiments of the present disclosure, the main controller 41 is electrically connected to the control device 1 to send the test enable signal Test_ENABLE to the control device 1 and receive the test pass signal Test_PASS from the control device 1 when the elevator is idle (as mentioned above, when the elevator is idle, the switching device 12 switches the phase terminals of the three-phase motor M to the capacitor circuit). In the case where the control device 1 is configured to be able to output the test fail signal Test_FAIL, the test fail signal Test_FAIL is also output to the main controller 41.

[0064] In one example, if the main controller 41 receives the test pass signal Test_PASS within a predetermined threshold period of time, it is considered that there is no open circuit in the brake circuit, and there is no need to change the state of the elevator. Conversely, if the main controller 41 does not receive the test pass signal Test_PASS within a predetermined threshold period of time, or receives the test fail signal Test_FAIL in the case where the control device 1 is configured to be able to output the test fail signal Test_FAIL, it is considered that there is an open circuit in the brake circuit, so that the elevator is deactivated for maintenance.

[0065] As shown in the diagram 51 and the diagram 52 in Figure 5 , the given test pass signal Test_PASS is a pulse signal with a voltage of 5v and a pulse width of 10 seconds, and the test fail signal Test_FAIL is a pulse signal with a voltage of 5v and a pulse width of 2 seconds, so the predetermined threshold period of time is 8 seconds. As shown, the main controller 41 receives the test pass signal Test_PASS from the control device 1 within 7 seconds after sending the test enable signal Test_ENABLE, so the state of the elevator is not changed.

[0066] In another example, in order to ensure the accuracy of the detection, if the main controller 41 does not receive the test pass signal Test_PASS within a predetermined threshold period of time or receives the test fail signal Test_FAIL in the case where the control device 1 is configured to be able to output the test fail signal Test_FAIL, the test enable signal Test_ENABLE is sent to the control device 1 again so as to perform the detection again, and in the case where the test pass signal Test_PASS is not received within the predetermined threshold period of time for the second time or the test fail signal Test_FAIL is received for the second time, the elevator is deactivated for maintenance.

[0067] As shown in the diagram 51 and the diagram 52 in Figure 5As shown in the diagram 53 and the diagram 54, the given test pass signal Test_PASS is a pulse signal with a voltage of 5V and a pulse width of 10 seconds, and the test pass signal Test_PASS is a pulse signal with a voltage of 5V and a pulse width of 2 seconds, so the predetermined threshold time period is 8 seconds. As shown, if the main controller 41 does not receive any signal from the control device 1 within 8 seconds after sending the test enable signal Test_ENABLE, the test enable signal Test_ENABLE is sent to the control device 1 again after a predetermined time period (3 seconds as shown in the diagram) from the last pulse of the test pass signal Test_PASS. After 7 seconds, the test pass signal Test_PASS is received, and the elevator state is not changed.

[0068] Figure 5 The examples of the above embodiments are only for illustrative purposes, and the form of the test enable signal and the test pass signal and the length of the predetermined threshold time period are not limited in the present disclosure.

[0069] Therefore, the control device and the control system according to the embodiments of the present disclosure not only provide the function of limiting the speed of the elevator during coasting, but also provide additional protection for the normal operation of the function, thereby improving the overall safety of the elevator.

[0070] The block diagrams of the circuits, devices, apparatuses, equipment, systems involved in the present disclosure are only for illustrative purposes and are not intended to require or imply that the connection, arrangement, configuration must be as shown in the block diagrams. As those skilled in the art will recognize, these circuits, devices, apparatuses, equipment, systems can be connected, arranged, configured in any way as long as the desired purpose can be achieved.

[0071] Those skilled in the art should understand that the above embodiments are only examples and are not limiting, and various modifications, combinations, partial combinations and replacements of the embodiments of the present disclosure can be made according to design requirements and other factors, as long as they are within the scope of the appended claims or their equivalents, which belong to the scope of protection of the present disclosure.

Claims

1. A control device for an elevator, the elevator having a three-phase motor as its traction machine and the three-phase motor being powered by a drive circuit, the control device comprising: a capacitor circuit for increasing braking torque of the three-phase motor when each phase terminal of the three-phase motor is connected therewith; a switching member for switching each phase terminal of the three-phase motor between the drive circuit and the capacitor circuit; and a detection member, in a case where each phase terminal of the three-phase motor is switched to the capacitor circuit by the switching member, in response to receiving a test enable signal, sequentially applying an excitation signal to one or more of a plurality of LC oscillation circuits in a braking circuit constituted by the capacitor circuit and each phase coil of the three-phase motor and detecting whether or not the LC oscillation circuit to which the excitation signal is applied generates LC oscillation, in a case where it is detected that each of the plurality of LC oscillation circuits generates LC oscillation, outputting a test pass signal to indicate that there is no open circuit in the braking circuit, wherein the detection member includes: a microcontroller that first generates the excitation signal to be applied to one of the plurality of LC oscillation circuits in response to receiving the test enable signal; and a detection circuit connected to each of the plurality of LC oscillation circuits to detect whether or not LC oscillation is generated in the LC oscillation circuit to which the excitation signal is applied and outputs a detection signal to the microcontroller indicating whether or not the LC oscillation is detected, wherein the microcontroller generates the excitation signal again to be applied to the next LC oscillation circuit of the plurality of LC oscillation circuits upon receiving the detection signal, and the microcontroller outputs the test pass signal in a case where each of a plurality of detection signals respectively corresponding to the plurality of LC oscillation circuits indicates that LC oscillation is detected.

2. The control device according to claim 1, wherein the detection member does not output any signal in a case where it is detected that at least one of the plurality of LC oscillation circuits does not generate LC oscillation.

3. The control device according to claim 2, wherein the detection member does not generate the excitation signal any more once it is detected that one of the plurality of LC oscillation circuits does not generate LC oscillation.

4. The control device according to claim 1, wherein the detection member outputs a test fail signal in a case where it is detected that at least one of the plurality of LC oscillation circuits does not generate LC oscillation, the test fail signal including information indicating in which of the plurality of LC oscillation circuits LC oscillation is not detected.

5. The control device according to claim 1, the excitation signal being a pulse width modulation signal, the detection member further comprising: a conversion circuit coupled between the microcontroller and the braking circuit for converting the pulse width modulation signal into a voltage signal or a current signal suitable for being applied to the LC oscillation circuit in the braking circuit.

6. The control device according to claim 1, wherein the detection circuit includes an operational amplifier and a comparator. ​ 7. The control device according to claim 1, wherein the capacitor circuit comprises capacitors connected in a star or delta connection.

8. The control device according to claim 1, further comprising: a power supply component for supplying power to the control device.

9. A control system for an elevator, comprising: a control device according to any one of claims 1-8; and a main controller for sending the test enable signal to the control device in case of an idle elevator.

10. The control system according to claim 9, wherein the main controller re-sends the test enable signal to the control device in response to not receiving the test passed signal within a predetermined threshold time period, and deactivates the elevator in response to not receiving the test passed signal a second time within a predetermined threshold time period.

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