Motor, motor controller and anti-power-on surge protection device and method thereof

Abstract

The invention discloses a motor, a motor controller and an anti-power-on surge protection device and method thereof, and the device comprises a first protection unit which is provided with a first current-limiting resistor module and a first switch module which are connected in parallel, and is connected between one phase of an access end of a three-phase AC power supply and a rectification unit; the second protection unit is provided with a second current-limiting resistor module and a second switch module which are connected in parallel, and is connected between the other phase of the three-phase alternating-current power supply access end and the rectification unit; after the motor controller is powered on, the first switch module and the second switch module are both switched off; after a set time, the first switch module and the second switch module are both closed. According to the scheme, the current limiting link is moved to the alternating current side, surge is suppressed in time before rectification, the whole motor controller is prevented from being damaged, and therefore the reliability of the motor controller is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of motors, and particularly relates to a power-on surge protection device, method, motor controller, and motor for a motor controller. Background Art

[0002] In a motor controller, power-on surge has become one of the inspection indicators for measuring the reliability of the motor controller. Power-on surge refers to the phenomenon that when an electronic device is first powered on, due to some components in the circuit, such as inductors and capacitors, it takes a period of time to reach a stable state, resulting in a large instantaneous increase in current or voltage.

[0003] In related solutions, a parallel branch of a PTC (Positive Temperature Coefficient) resistor and a relay is added to the DC circuit after the rectifier circuit to reduce the surge current generated during power-on. Although the above power-on surge protection circuit can limit the surge current on the DC side, if the surge current on the AC side before rectification is too large (such as a power grid transient spike), it cannot effectively suppress the large surge on the DC side after rectification, resulting in damage to the motor controller.

[0004] The above content is only used to assist in understanding the technical solution of the present invention, and does not represent an admission that the above content is prior art. Summary of the Invention

[0005] The purpose of the present invention is to provide a power-on surge protection device, method, motor controller, and motor for a motor controller, so as to solve the problem in related solutions that the large surge on the DC side after rectification cannot be effectively suppressed, resulting in damage to the motor controller, and be able to suppress the surge in time before rectification, avoiding the motor controller from being subjected to high-voltage impact, thereby improving the reliability and energy efficiency of the motor controller.

[0006] The present invention provides a power-on surge protection device for a motor controller. The motor controller has a three-phase AC power supply access terminal and a rectification unit. The power-on surge protection device for the motor controller includes:

[0007] A first protection unit is connected between one of the three-phase AC power supply access terminals and the rectification unit. The first protection unit has a first current-limiting resistor module and a first switch module, and the first current-limiting resistor module and the first switch module are arranged in parallel;

[0008] A second protection unit is connected between another one of the three-phase AC power supply access terminals and the rectification unit. The second protection unit has a second current-limiting resistor module and a second switch module, and the second current-limiting resistor module and the second switch module are arranged in parallel;

[0009] After the motor controller is powered on, both the first switch module and the second switch module are disconnected, so that both the first current-limiting resistor module and the second current-limiting resistor module are connected; after a set time, both the first switch module and the second switch module are closed, so that both the first current-limiting resistor module and the second current-limiting resistor module are cut out.

[0010] In some embodiments, the three-phase AC power supply access terminal has a live wire L1, a live wire L2, and a live wire L3; the anti-power-on surge protection device further includes:

[0011] A third protection unit, having a first filtering module, a second filtering module, a third filtering module, and a discharge tube module; wherein, the first filtering module is connected between the live wire L1 and the discharge tube module; the second filtering module is connected between the live wire L2 and the discharge tube module; the third filtering module is connected between the live wire L3 and the discharge tube module; the discharge tube module is connected between the common end of the first filtering module, the second filtering module, and the third filtering module and the ground.

[0012] In some embodiments, the first filtering module includes a first resistor module and a first capacitor module, and the first capacitor module is connected in parallel across the first resistor module; the second filtering module includes a second resistor module and a second capacitor module, and the second capacitor module is connected in parallel across the second resistor module; the third filtering module includes a third resistor module and a third capacitor module, and the third capacitor module is connected in parallel across the third resistor module.

[0013] In some embodiments, the anti-power-on surge protection device further includes:

[0014] A common-mode inductor unit, the input end of the common-mode inductor unit is connected to the three-phase AC power supply access terminal, and one phase of the output end of the common-mode inductor unit is connected to the first protection unit; the other phase of the output end of the common-mode inductor unit is connected to the second protection unit.

[0015] In some embodiments, the first current-limiting resistor module includes a first thermistor module, the second current-limiting resistor module includes a second thermistor module, the first switch module includes a first relay module, and the second switch module includes a second relay module;

[0016] The first relay module has a coil and a normally open contact; the first thermistor module and the normally open contact of the first relay module are connected in parallel;

[0017] The second relay module has a coil and a normally open contact; the second thermistor module and the normally open contact of the second relay module are arranged in parallel.

[0018] In some embodiments, the first protection unit further includes: a first diode module, the first diode module is connected in parallel across the two ends of the coil of the first relay module; the positive electrode of the first diode module is grounded, and the negative electrode of the first diode module is connected to a preset DC power supply;

[0019] The second protection unit further includes: a second diode module, the second diode module is connected in parallel across the two ends of the coil of the second relay module; the positive electrode of the second diode module is grounded, and the negative electrode of the second diode module is connected to a preset DC power supply.

[0020] In some embodiments, the first protection unit further includes: a fourth capacitor module and a fifth capacitor module; wherein, the fourth capacitor module is connected in parallel with the first diode module; the fifth capacitor module is connected in parallel with the second diode module.

[0021] Matched with the above device, on the other hand, the present invention provides a motor controller, including: the anti-power-on surge protection device of the above-mentioned motor controller.

[0022] Matched with the above device, on the other hand, the present invention provides a motor, including: the anti-power-on surge protection device of the above-mentioned motor controller, or the above-mentioned motor controller.

[0023] Matched with the above device, on the other hand, the present invention provides a method for protecting a motor controller against power-on surge corresponding to the anti-power-on surge protection device of the motor controller, including:

[0024] After the motor controller is powered on, control both the first switch module and the second switch module to be disconnected, so that both the first current-limiting resistor module and the second current-limiting resistor module are connected;

[0025] After a set time, control both the first switch module and the second switch module to be closed, so that both the first current-limiting resistor module and the second current-limiting resistor module are cut out.

[0026] Thus, in the solution of the present invention, by moving the current limiting link to the AC side, the surge is suppressed in time before rectification, avoiding damage to the motor controller. At the same time, by configuring protection units on any two of the three live wires, dual protection on the two live wires can be achieved, ensuring that the current on each live wire can be effectively controlled, thereby improving the reliability of the motor controller. Moreover, by completely bypassing the current limiting resistor module by the switch module in the steady state, the problems of temperature rise and energy consumption caused by the continuous operation of the current limiting resistor module in the traditional solution are eliminated, thereby improving the energy efficiency of the motor controller.

[0027] Other features and advantages of the present invention will be described in the following specification, and, in part, will be obvious from the specification, or will be understood by implementing the present invention.

[0028] The technical solution of the present invention will be further described in detail below through the drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic structural diagram of an embodiment of the anti-power-on surge protection device of the motor controller of the present invention;

[0030] Figure 2 is a schematic structural diagram of an embodiment of the anti-power-on surge protection circuit of the motor controller of the present invention;

[0031] Figure 3 is a schematic structural diagram of another embodiment of the anti-power-on surge protection circuit of the motor controller of the present invention;

[0032] Figure 4 is a schematic structural diagram of another embodiment of the anti-power-on surge protection circuit of the motor controller of the present invention;

[0033] Figure 5 is a schematic structural diagram of an embodiment of the anti-power-on surge protection circuit in the related solution. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0035] The rectifier bridge in the motor controller, as the core link for converting alternating current to direct current, is directly exposed to grid fluctuations. When there are transient high-voltage spikes on the AC input side (such as lightning induction, voltage surges caused by large load switching), such high-frequency and high-energy surges will be quickly transmitted to the DC bus through the rectifier diodes. In the relevant solutions, the parallel branch of the thermistor and the relay is deployed on the DC side after rectification, and its scope of action is limited to the DC circuit, and it cannot absorb or clamp the energy invading from the AC side. When the rectifier diode is subjected to a transient impact exceeding the reverse breakdown voltage, avalanche breakdown is likely to occur, and the DC bus capacitor may cause the electrolyte to boil or even burst due to overvoltage, resulting in damage to the entire motor controller.

[0036] Figure 5 It is a schematic structural diagram of an embodiment of the protection circuit against power-on surge in the relevant solution. As Figure 5 shown, it includes live wire L1, live wire L2, live wire L3, common-mode inductor J1, rectifier bridge D3~D8, thermistor PTC1, relay K1, diode D1, capacitor C2, bus capacitor C3, bus capacitor C4, and switching power supply circuit. The three windings of the common-mode inductor J1 use live wire L1, live wire L2, and live wire L3. Live wire L1, live wire L2, and live wire L3 pass through the magnetic core of the common-mode inductor J1 in parallel and are connected to the three-phase input terminals of the rectifier bridge. Among them, the three-phase input terminals of the rectifier bridge are the three-phase input terminals corresponding to the phase wires of live wire L1, live wire L2, and live wire L3. The surge current at the moment of power-on of the motor controller is respectively generated by the grid live wires A, B, and C contacting the motor controller live wires L1, L2, and L3. When the motor controller is powered on, in the rectified DC circuit, the thermistor PTC1 is initially in a cold state (low resistance value), allowing the surge current to pass through. The thermistor PTC1 heats up with the current, and its resistance value increases, gradually restricting the current. During normal operation, the relay K1 needs to remain closed to maintain power supply, and the thermistor PTC1 is still connected in series in the circuit and may continuously generate heat and consume energy.

[0037] When there are transient high-voltage spikes on the AC input side, the surge will be quickly transmitted to the DC bus through the rectifier bridge. The parallel branch of the thermistor PTC1 and the relay K1 is deployed on the DC side after rectification, and it cannot effectively suppress the large surge on the DC side after rectification, resulting in breakdown of the rectifier diode, overvoltage of the bus capacitor, or damage to the entire motor controller.

[0038] Therefore, in the related solutions, the performance and reliability of the motor controller still need to be further improved. Therefore, it is necessary to design a protection circuit against power-on surge for the motor controller to solve the above problems. Thus, the solution of the present invention proposes a protection device against power-on surge for the motor controller, which can be a protection circuit against power-on surge for the motor controller. The current-limiting link is moved to the AC side to suppress the surge in time before rectification, avoiding the high-voltage impact on the rectifier bridge and the bus capacitor. Moreover, due to the adoption of the dual-firewire independent protection mechanism, the risk of single-point failure is avoided. Furthermore, the relay completely bypasses the PTC resistor in the steady state, eliminating the temperature rise and energy consumption problems of the PTC resistor in continuous operation in the traditional solution, thereby improving the reliability and energy efficiency of the motor controller.

[0039] According to an embodiment of the present invention, there is provided a protection device against power-on surge for a motor controller. Refer to Figure 1 the schematic structural diagram of an embodiment of the device of the present invention shown in Figure 1 As shown, the protection device against power-on surge for the motor controller includes:

[0040] A first protection unit (such as Figure 2 circuit 1 shown), connected between one of the three-phase AC power access terminals and the rectification unit; the first protection unit has a first current-limiting resistor module and a first switch module, and the first current-limiting resistor module and the first switch module are arranged in parallel.

[0041] Wherein, one of the three-phase AC power access terminals refers to any one of the live wires L1, L2, and L3.

[0042] A second protection unit (such as Figure 2 circuit 2 shown), connected between another one of the three-phase AC power access terminals and the rectification unit; the second protection unit has a second current-limiting resistor module and a second switch module, and the second current-limiting resistor module and the second switch module are arranged in parallel.

[0043] Wherein, the other one of the three-phase AC power access terminals refers to one of the remaining two phases other than the phase connected by the first protection unit.

[0044] After the motor controller is powered on, both the first switch module and the second switch module are disconnected, so that both the first current-limiting resistor module and the second current-limiting resistor module are connected; after a set time, both the first switch module and the second switch module are closed, so that both the first current-limiting resistor module and the second current-limiting resistor module are cut out.

[0045] Figure 2The figure is a schematic structural diagram of an embodiment of the protection circuit against power-on surge for the motor controller of the present invention. As Figure 2 shown, the protection circuit against power-on surge for the motor controller includes: Circuit 1 and Circuit 2.

[0046] Circuit 1 is connected between one of the three-phase AC power access terminals and the rectification unit; Circuit 1 has a first current-limiting resistor module and a first switch module, and the first current-limiting resistor module and the first switch module are arranged in parallel.

[0047] Circuit 2 is connected between another one of the three-phase AC power access terminals and the rectification unit; Circuit 2 has a second current-limiting resistor module and a second switch module, and the second current-limiting resistor module and the second switch module are arranged in parallel.

[0048] Figure 2 The example shown is based on the relevant solution Figure 5 On the basis of the example shown, the current-limiting link (i.e., the protection unit) is moved to the AC side to suppress the surge in time before rectification, avoiding the rectifier bridge and the bus capacitor from being subjected to high-voltage impact. At the same time, by configuring the protection unit on any two of the three-phase live wires, double protection on the two live wires can be achieved to ensure that the current on each live wire can be effectively controlled.

[0049] Specifically, a protection unit can be selected and configured in any one of the three groups of phase wires L1-L2, L2-L3, or L1-L3 of the live wire L1, live wire L2, and live wire L3. As Figure 3 shown, the protection unit is selected and configured in the group of phase wires L1-L3. Circuit 1 is connected between the live wire L1 of the three-phase AC power access terminal and the rectification unit. Circuit 2 is connected between the live wire L3 of the three-phase AC power access terminal and the rectification unit.

[0050] Among them, the rectification unit can be a three-phase full-bridge rectification circuit composed of 6 diodes (D3-D8), and each phase is composed of 2 diodes to form a bridge arm. The cathodes of the upper bridge arm D3, D5, and D7 are commonly connected to the positive pole of the DC bus, and the anodes of the lower bridge arm D4, D6, and D8 are commonly connected to the negative pole of the DC bus. The first protection unit is connected between the live wire L1 of the three-phase AC power access terminal and the common terminal of D3 and D4. The second protection unit is connected between the live wire L3 of the three-phase AC power access terminal and the common terminal of D7 and D8. The live wire L2 of the three-phase AC power access terminal is directly connected to the common terminal of D5 and D6. The three-phase full-bridge rectification circuit is preferably a 50A / 1600V rectifier bridge.

[0051] After the motor controller is powered on, both the first switch module and the second switch module are disconnected, so that both the first current-limiting resistor module and the second current-limiting resistor module are connected to the main circuit of the motor controller; after a set time, when a preset DC power supply supplies power to the first switch module and the second switch module, both the first switch module and the second switch module are closed, so that both the first current-limiting resistor module and the second current-limiting resistor module are cut out from the main circuit of the motor controller.

[0052] A protection circuit for preventing power-on surge of a motor controller proposed by the solution of the present invention moves the current-limiting link to the AC side, suppresses the surge in time before rectification, and avoids damage to the motor controller. At the same time, by configuring protection units on any two of the three-phase live wires, dual protection on the two live wires can be achieved, ensuring that the current on each live wire can be effectively controlled, thereby improving the reliability of the motor controller. Moreover, by completely bypassing the current-limiting resistor module at steady state through the switch module, the problems of temperature rise and energy consumption of the continuous operation of the current-limiting resistor module in the traditional solution are eliminated, thereby improving the energy efficiency of the motor controller.

[0053] In some embodiments, the power-on surge protection device further includes:

[0054] A third protection unit, having a first filtering module ( Figure 3 RV1 and C1 shown), a second filtering module ( Figure 3 RV2 and C2 shown), a third filtering module ( Figure 3 RV3 and C3 shown), and a discharge tube module ( Figure 3 TVS1 shown); wherein, the first filtering module is connected between the live wire L1 and the discharge tube module; the second filtering module is connected between the live wire L2 and the discharge tube module; the third filtering module is connected between the live wire L3 and the discharge tube module; the discharge tube module is connected between the common end of the first filtering module, the second filtering module, and the third filtering module and the ground.

[0055] In some embodiments, the first filtering module includes: a first resistor module ( Figure 3 RV1 shown) and a first capacitor module ( Figure 3 C1 shown), and the first capacitor module is connected in parallel across the first resistor module; the second filtering module includes: a second resistor module ( Figure 3 RV2 shown) and a second capacitor module ( Figure 3 C2 shown), and the second capacitor module is connected in parallel across the second resistor module; the third filtering module includes: a third resistor module ( Figure 3 RV3 shown) and a third capacitor module (Figure 3 The third capacitor module (C3) shown is connected in parallel across the two ends of the third resistor module.

[0056] Among them, the first resistor module can adopt a first varistor module, the second resistor module can adopt a second varistor module, and the third resistor module can adopt a third varistor module.

[0057] In the solution of the present invention, the first filtering module, the second filtering module, the third filtering module and the discharge tube module construct a double barrier for AC-side surge protection through a cooperative mechanism of fast clamping and large-current discharge. The first filtering module, the second filtering module, and the third filtering module are responsible for suppressing high-frequency and medium-energy surges, and the discharge tube module deals with low-frequency and high-energy impacts. Through collaborative design, multi-stage suppression of transient surges on the AC side is achieved, improving the reliability of the motor controller.

[0058] In Figure 3 In the example shown, Circuit 3 includes: varistor RV1, varistor RV2, and varistor RV3. The varistor RV1 is connected between the live wire L1 and the discharge tube TVS1; the varistor RV2 is connected between the live wire L2 and the discharge tube TVS1; the varistor RV3 is connected between the live wire L3 and the discharge tube TVS1; the discharge tube TVS1 is connected between the common terminal of the varistor RV1, the varistor RV2, and the varistor RV3 and the ground. The capacitor C1 is connected in parallel across the varistor RV1; the capacitor C2 is connected in parallel across the varistor RV2; the capacitor C3 is connected in parallel across the varistor RV3.

[0059] The resistance values of the varistor RV1, the varistor RV2, and the varistor RV3 change non-linearly with the applied voltage. When the grid voltage is lower than the varistor voltages of the varistor RV1, the varistor RV2, and the varistor RV3, the varistor RV1, the varistor RV2, and the varistor RV3 present a high-resistance state and have no effect on the circuit. When a transient overvoltage occurs on the AC side (such as lightning strikes, load switching), the varistor RV1, the varistor RV2, and the varistor RV3 turn into a low-resistance state, and the surge current is discharged through the varistor RV1, the varistor RV2, and the varistor RV3, clamping the voltage within a safe range to protect the rectifier bridge (D3 - D8), the bus capacitor C6, and the bus capacitor C7 from high-voltage impacts.

[0060] The response time of the varistor RV1, the varistor RV2, and the varistor RV3 is usually 25 - 50 ns, but there may be a delay for extremely high-frequency transient spikes. The high-frequency transient spikes are quickly discharged through the low-impedance paths of the capacitor C1, the capacitor C2, and the capacitor C3, forming a parallel discharge channel with the varistor RV1, the varistor RV2, and the varistor RV3, improving the overall response speed.

[0061] Among them, the varistors RV1, RV2, and RV3 can be selected according to the working voltage and temperature conditions, and are preferably MYN15-621KM.

[0062] Among them, the capacitors C1, C2, and C3 are preferably valued at 0.22 μf.

[0063] The discharge tube TVS1 is filled with inert gas inside. When the voltage exceeds the breakdown voltage, the gas ionizes to form a conductive channel. When the grid voltage is lower than the breakdown voltage of the discharge tube TVS1, the discharge tube TVS1 is in a high-resistance state. When there is still residual high voltage after the varistors RV1, RV2, and RV3 are clamped or the varistors RV1, RV2, and RV3 fail, the voltage across the discharge tube TVS1 exceeds the breakdown voltage, and the gas ionizes and conducts. The surge current is directly discharged to the ground through the discharge tube TVS1, avoiding energy impact on the subsequent circuit. After the surge ends, the discharge tube TVS1 returns to the high-resistance state.

[0064] Among them, the discharge tube TVS1 can be selected according to the working voltage, the discharge current of the discharge tube, and the response rate, and is preferably FA55-362.

[0065] The varistors RV1, RV2, and RV3 and the discharge tube TVS1 construct a double barrier for surge protection on the AC side through the cooperative mechanism of rapid clamping and large-current discharge. The varistors RV1, RV2, RV3, capacitors C1, C2, and C3 are responsible for suppressing high-frequency and medium-energy surges, and the discharge tube TVS1 responds to low-frequency and high-energy impacts. Through cooperative design, multi-stage suppression of transient surges on the AC side is achieved, improving the reliability of the motor controller.

[0066] In some embodiments, the anti-power-on surge protection device further includes: a common-mode inductance unit (such as Figure 3 or Figure 4 the J1 shown), the input end of the common-mode inductance unit is connected to the three-phase AC power access end, and one phase of the output end of the common-mode inductance unit is connected to the first protection unit; the other phase of the output end of the common-mode inductance unit is connected to the second protection unit.

[0067] In Figure 3 or Figure 4 the example shown, the common-mode inductance J1 has three independent windings with the same number of turns, and the three windings use the live wires L1, L2, and L3.

[0068] When common-mode interference (such as a surge) appears, the co-directional interference currents on the three live wires will generate a superimposed magnetic flux in the magnetic core, and the inductor presents a high impedance, thereby suppressing the interference.

[0069] In the solution of the present invention, at the moment of power-on, the surge current passes through the windings of the live wires L1, L2, L3 and the common-mode inductor J1. The inductance characteristic of the common-mode inductor J1 can slow down the sudden change rate of the current, thereby reducing the peak value of the surge current, blocking the influence of external common-mode interference on the rectifier bridge, the bus capacitor and the switching power supply, and improving the stability of the motor controller.

[0070] In some embodiments, the first current-limiting resistor module includes a first thermistor module (such as Figure 2 , Figure 3 or Figure 4 the thermistor PTC1 shown), the second current-limiting resistor module includes a second thermistor module (such as Figure 2 , Figure 3 or Figure 4 the thermistor PTC2 shown), the first switch module includes a first relay module (such as Figure 2 , Figure 3 or Figure 4 the relay K1 shown), and the second switch module includes a second relay module (such as Figure 2 , Figure 3 or Figure 4 the relay K2 shown).

[0071] The first relay module has a coil and a normally open contact; the first thermistor module and the normally open contact of the first relay module are connected in parallel.

[0072] The second relay module has a coil and a normally open contact; the second thermistor module and the normally open contact of the second relay module are connected in parallel.

[0073] After the motor controller is powered on, the normally open contacts of the first relay module and the second relay module are both disconnected, so that the first current-limiting resistor module and the second current-limiting resistor module are both connected to the main circuit of the motor controller; after a set time, when a preset DC power supply supplies power to the coils of the first relay module and the second relay module, the normally open contacts of the first relay module and the second relay module are both closed, so that the first current-limiting resistor module and the second current-limiting resistor module are both cut out of the main circuit of the motor controller.

[0074] In the solution of the present invention, after the motor controller is powered on, the surge current flows through the first current-limiting resistor module and the second current-limiting resistor module, effectively protecting the circuit from surge damage. After a set time, when the preset DC power supply supplies power to the coils of the first relay module and the second relay module, the first relay module and the second relay module completely bypass the first current-limiting resistor module and the second current-limiting resistor module, eliminating the temperature rise and energy consumption problems of the thermistor continuously working in the traditional solution, thereby improving the energy efficiency of the motor controller.

[0075] In Figure 2 、 Figure 3 or Figure 4 In the example shown, the relay K1 has a coil and a normally open contact, and the thermistor PTC1 is connected in parallel with the normally open contact of the relay K1. The relay K2 has a coil and a normally open contact, and the thermistor PTC1 is connected in parallel with the normally open contact of the relay K2.

[0076] The resistance values of the thermistor PTC1 and the thermistor PTC2 can be selected according to the measured temperature rise that meets the design requirements, the magnitude of the power-on surge current value, the three-phase working voltage, and the working current. The resistance values of the thermistor PTC1 and the thermistor PTC2 are preferably 50Ω. The relays K1 and K2 can be selected according to the steady-state current. For example, the working current is less than 16A and there is sufficient margin. The relays K1 and K2 are preferably selected as 100A / 600VAC.

[0077] After the motor controller is powered on, the normally open contacts of the relays K1 and K2 are both disconnected, so that the thermistors PTC1 and PTC2 are both connected to the main circuit of the motor controller; after a set time, for example, 10ms after the motor controller is powered on, when the preset DC power supply (such as a 12V power supply) supplies power to the coils of the relays K1 and K2, the normally open contacts of the relays K1 and K2 are both closed, so that the thermistors PTC1 and PTC2 are both cut out of the main circuit of the motor controller.

[0078] After the motor controller is powered on, the surge current flows through the thermistors PTC1 and PTC2, effectively protecting the circuit from surge damage. After a set time, when the preset DC power supply supplies power to the coils of the relays K1 and K2, the relays K1 and K2 completely bypass the thermistors PTC1 and PTC2, eliminating the temperature rise and energy consumption problems of the thermistor continuously working in the traditional solution, thereby improving the energy efficiency of the motor controller.

[0079] In some embodiments, the first protection unit further includes: a first diode module (such as Figure 2 、 Figure 3 or Figure 4The diode D1 shown), the first diode module is connected in parallel across the coil of the first relay module; the positive electrode of the first diode module is grounded, and the negative electrode of the first diode module is connected to a preset DC power supply;

[0080] The second protection unit further includes: a second diode module (such as Figure 2 , Figure 3 or Figure 4 the diode D2 shown), the second diode module is connected in parallel across the coil of the second relay module; the positive electrode of the second diode module is grounded, and the negative electrode of the second diode module is connected to a preset DC power supply.

[0081] In the solution of the present invention, when the coil of the relay is powered off, due to the inductance characteristic, a reverse electromotive force is generated in the coil of the relay, which may be as high as dozens to hundreds of volts. The first diode module and the second diode module provide a low-impedance path for this reverse voltage, release the energy through the coil-diode loop, and avoid high-voltage breakdown of the switching element, thereby improving the reliability of the motor controller.

[0082] In Figure 2 , Figure 3 or Figure 4 the example shown, the diode D1 is connected in parallel across the coil of the relay K1; the positive electrode of the diode D1 is grounded, and the negative electrode of the diode D1 is connected to a preset DC power supply (such as a 12V power supply).

[0083] The diode D2 is connected in parallel across the coil of the relay K2; the positive electrode of the diode D2 is grounded, and the negative electrode of the diode D2 is connected to a preset DC power supply (such as a 12V power supply).

[0084] Among them, the diode D1 and the diode D2 can be selected according to satisfying high-frequency filtering and overvoltage protection. The diode D1 and the diode D2 are preferably 1N4148W, which are high-speed switching diodes with a reverse recovery time of 4 ns.

[0085] The diode D1 and the diode D2 provide a low-impedance path for the reverse voltage, release the energy through the coil-diode loop, and avoid high-voltage breakdown of the switching element, thereby improving the reliability of the motor controller.

[0086] In some embodiments, the first protection unit further includes: a fourth capacitor module (such as Figure 4 the capacitor C4 shown) and a fifth capacitor module (such as Figure 4 the capacitor C5 shown); wherein, the fourth capacitor module is connected in parallel with the first diode module; the fifth capacitor module is connected in parallel with the second diode module.

[0087] In the solution of the present invention, when the coils of the first relay module and the second relay module are powered off, the inductive current of the coils of the first relay module and the second relay module passes through the first diode module and the second diode module. The fourth capacitor module and the fifth capacitor module can absorb part of the energy, slow down the voltage rising speed, and reduce the peak voltage.

[0088] In Figure 4 the example shown, capacitor C4 is connected in parallel with diode D1; capacitor C5 is connected in parallel with diode D2. Among them, the values of capacitor C4 and capacitor C5 can be selected according to the requirements of high-frequency filtering and the working voltage of the capacitor should be greater than 12V. The values of capacitor C4 and capacitor C5 are preferably 0.1 μf.

[0089] When the coils of relay K1 and relay K2 are powered off, the inductive current of the coils of relay K1 and relay K2 passes through diode D1 and diode D2. Capacitor C4 and capacitor C5 can absorb part of the energy, slow down the voltage rising speed, and reduce the peak voltage.

[0090] According to an embodiment of the present invention, there is also provided a motor controller corresponding to the anti-power-on surge protection device of the motor controller. As shown in the attached Figure 2 , attached Figure 3 , and attached Figure 4 shown, the motor controller may include: the anti-power-on surge protection device of the above-mentioned motor controller, a rectification unit, a bus capacitor, and a switching power supply circuit.

[0091] Among them, in the anti-power-on surge protection device of the above-mentioned motor controller, it includes:

[0092] As Figure 1 shown, the anti-power-on surge protection device of the motor controller includes:

[0093] The first protection unit (circuit 1 as Figure 2 shown) is connected between one of the three-phase AC power access terminals and the rectification unit; the first protection unit has a first current-limiting resistor module and a first switch module, and the first current-limiting resistor module and the first switch module are arranged in parallel.

[0094] Among them, one of the three-phase AC power access terminals refers to any one of live wire L1, live wire L2, and live wire L3.

[0095] The second protection unit (circuit 2 as Figure 2 shown) is connected between another one of the three-phase AC power access terminals and the rectification unit; the second protection unit has a second current-limiting resistor module and a second switch module, and the second current-limiting resistor module and the second switch module are arranged in parallel.

[0096] Among them, the other phase of the three-phase AC power supply access terminal refers to one of the remaining two phases other than the phase connected to the first protection unit.

[0097] After the motor controller is powered on, both the first switch module and the second switch module are disconnected, so that both the first current-limiting resistor module and the second current-limiting resistor module are connected; after a set time, both the first switch module and the second switch module are closed, so that both the first current-limiting resistor module and the second current-limiting resistor module are cut out.

[0098] A protection circuit for preventing power-on surge of a motor controller proposed by the solution of the present invention suppresses the surge in time before rectification by moving the current-limiting link to the AC side, avoiding damage to the motor controller. At the same time, by configuring protection units on any two of the three live wires, double protection on the two live wires can be achieved, ensuring that the current on each live wire can be effectively controlled, thereby improving the reliability of the motor controller. Moreover, by completely bypassing the current-limiting resistor module by the switch module in the steady state, the problems of temperature rise and energy consumption of the continuous operation of the current-limiting resistor module in the traditional solution are eliminated, thereby improving the energy efficiency of the motor controller.

[0099] In some embodiments, the power-on surge protection device further includes:

[0100] A third protection unit, having a first filtering module ( Figure 3 RV1 and C1 shown), a second filtering module ( Figure 3 RV2 and C2 shown), a third filtering module ( Figure 3 RV3 and C3 shown), and a discharge tube module ( Figure 3 TVS1 shown); wherein, the first filtering module is connected between the live wire L1 and the discharge tube module; the second filtering module is connected between the live wire L2 and the discharge tube module; the third filtering module is connected between the live wire L3 and the discharge tube module; the discharge tube module is connected between the common end of the first filtering module, the second filtering module, and the third filtering module and the ground.

[0101] In some embodiments, the first filtering module includes: a first resistor module ( Figure 3 RV1 shown) and a first capacitor module ( Figure 3 C1 shown), the first capacitor module is connected in parallel across the first resistor module; the second filtering module includes: a second resistor module ( Figure 3 RV2 shown) and a second capacitor module ( Figure 3 C2 shown), the second capacitor module is connected in parallel across the second resistor module; the third filtering module includes: a third resistor module (Figure 3 the RV3) shown and the third capacitor module ( Figure 3 C3) shown, and the third capacitor module is connected in parallel across both ends of the third resistor module.

[0102] In the solution of the present invention, the first filtering module, the second filtering module, the third filtering module and the discharge tube module construct a double barrier for AC side surge protection through the collaborative mechanism of fast clamping and large current discharging. The first filtering module, the second filtering module and the third filtering module are responsible for suppressing high-frequency and medium-energy surges, and the discharge tube module deals with low-frequency and high-energy impacts. Through collaborative design, multi-stage suppression of transient surges on the AC side is achieved, improving the reliability of the motor controller.

[0103] In some embodiments, the power-on surge protection device further includes: a common mode inductance unit (such as Figure 3 or Figure 4 J1) shown, the input end of the common mode inductance unit is connected to the three-phase AC power access end, and one phase of the output end of the common mode inductance unit is connected to the first protection unit; the other phase of the output end of the common mode inductance unit is connected to the second protection unit.

[0104] In the solution of the present invention, at the moment of power-on, the surge current passes through the windings of the live wires L1, L2, L3 and the common mode inductance J1. The inductance characteristic of the common mode inductance J1 will slow down the sudden change rate of the current, thereby reducing the peak value of the surge current, blocking the influence of external common mode interference on the rectifier bridge, bus capacitor and switching power supply, and improving the stability of the motor controller.

[0105] In some embodiments, the first current limiting resistor module includes a first thermistor module (such as Figure 2 , Figure 3 or Figure 4 the thermistor PTC1) shown, the second current limiting resistor module includes a second thermistor module (such as Figure 2 , Figure 3 or Figure 4 the thermistor PTC2) shown, the first switch module includes a first relay module (such as Figure 2 , Figure 3 or Figure 4 the relay K1) shown, the second switch module includes a second relay module (such as Figure 2 , Figure 3 or Figure 4 the relay K2) shown.

[0106] The first relay module has a coil and a normally open contact; the first thermistor module and the normally open contact of the first relay module are arranged in parallel.

[0107] The second relay module has a coil and a normally open contact; the second thermistor module is arranged in parallel with the normally open contact of the second relay module.

[0108] After the motor controller is powered on, the first switch module and the second switch module are both turned off, so that the first current limiting resistor module and the second current limiting resistor module are both connected to the main circuit of the motor controller; after a set time, when a preset DC power supply supplies power to the first switch module and the second switch module, the first switch module and the second switch module are both closed, so that the first current limiting resistor module and the second current limiting resistor module are both cut out of the main circuit of the motor controller.

[0109] In the solution of the present invention, after the motor controller is powered on, the surge current flows through the first current limiting resistor module and the second current limiting resistor module, effectively protecting the circuit from surge damage. After a set time, when a preset DC power supply supplies power to the first switch module and the second switch module, the first switch module and the second switch module completely bypass the first current limiting resistor module and the second current limiting resistor module, eliminating the temperature rise and energy consumption problems of the continuous operation of the thermistor in the traditional solution, thereby improving the energy efficiency of the motor controller.

[0110] In some embodiments, the first protection unit further includes: a first diode module (such as Figure 2 , Figure 3 or Figure 4 the diode D1 shown), the first diode module is connected in parallel across the coil of the first relay module; the positive electrode of the first diode module is grounded, and the negative electrode of the first diode module is connected to a preset DC power supply;

[0111] The second protection unit further includes: a second diode module (such as Figure 2 , Figure 3 or Figure 4 the diode D2 shown), the second diode module is connected in parallel across the coil of the second relay module; the positive electrode of the second diode module is grounded, and the negative electrode of the second diode module is connected to a preset DC power supply.

[0112] In the solution of the present invention, the first diode module and the second diode module provide a low impedance path for the reverse voltage, release the energy through the coil-diode loop, and avoid high voltage breakdown of the switching element, thereby improving the reliability of the motor controller.

[0113] In some embodiments, the first protection unit further includes: a fourth capacitor module (such as Figure 4 the capacitor C4 shown) and a fifth capacitor module (such as Figure 4the capacitor C5 shown); wherein, the fourth capacitor module is connected in parallel with the first diode module; the fifth capacitor module is connected in parallel with the second diode module.

[0114] In the solution of the present invention, when the coils of the first relay module and the second relay module are powered off, the inductive current of the coils of the first relay module and the second relay module passes through the first diode module and the second diode module. The fourth capacitor module and the fifth capacitor module can absorb part of the energy, slow down the voltage rising speed, and reduce the peak voltage.

[0115] Since the processing and functions implemented by the motor controller in this embodiment basically correspond to the embodiments, principles, and examples of the device, for the details not described in the description of this embodiment, reference can be made to the relevant descriptions in the foregoing embodiments, and details will not be repeated here.

[0116] According to an embodiment of the present invention, there is also provided a motor corresponding to the anti-power-on surge protection device of the motor controller. The motor may include: the anti-power-on surge protection device of the motor controller described above, or the motor controller described above.

[0117] Since the processing and functions implemented by the motor in this embodiment basically correspond to the embodiments, principles, and examples of the device, for the details not described in the description of this embodiment, reference can be made to the relevant descriptions in the foregoing embodiments, and details will not be repeated here.

[0118] According to an embodiment of the present invention, there is also provided a method for protecting against power-on surge of a motor controller corresponding to the anti-power-on surge protection device of the motor controller.

[0119] The following combines the attached Figure 1 The anti-power-on surge protection device of the motor controller shown to describe the anti-power-on surge protection method of the motor controller.

[0120] The anti-power-on surge protection method of the motor controller includes:

[0121] After the motor controller is powered on, control both the first switch module and the second switch module to be disconnected, so that both the first current-limiting resistor module and the second current-limiting resistor module are connected;

[0122] After a set time, control both the first switch module and the second switch module to be closed, so that both the first current-limiting resistor module and the second current-limiting resistor module are cut out.

[0123] After the motor controller is powered on, both the first switch module and the second switch module are disconnected, so that both the first current-limiting resistor module and the second current-limiting resistor module are connected to the main circuit of the motor controller; after a set time, when a preset DC power supply supplies power to the first switch module and the second switch module, both the first switch module and the second switch module are closed, so that both the first current-limiting resistor module and the second current-limiting resistor module are cut out of the main circuit of the motor controller.

[0124] Combined with the Figure 2 , the Figure 3 , and the Figure 4 The anti-power-on surge protection circuit of the motor controller shown. After the motor controller is powered on, the normally open contacts of relay K1 and relay K2 are both disconnected, so that the thermistor PTC1 and the thermistor PTC2 are both connected to the main circuit of the motor controller; after a set time, for example, 10 ms after the motor controller is powered on, when a preset DC power supply (such as a 12V power supply) supplies power to the coils of relay K1 and relay K2, the normally open contacts of relay K1 and relay K2 are both closed, so that the thermistor PTC1 and the thermistor PTC2 are both cut out of the main circuit of the motor controller.

[0125] A protection method for preventing power-on surge of a motor controller proposed by the solution of the present invention. By moving the current-limiting link to the AC side and suppressing the surge in time before rectification, damage to the motor controller is avoided. At the same time, by configuring protection units on any two of the three-phase live wires, double protection on the two live wires can be achieved, ensuring that the current on each live wire can be effectively controlled, thereby improving the reliability of the motor controller. Moreover, by completely bypassing the current-limiting resistor module at steady state through the switch module, the problems of temperature rise and energy consumption of the continuous operation of the current-limiting resistor module in the traditional solution are eliminated, thereby improving the energy efficiency of the motor controller.

[0126] Since the processing and functions implemented by the method of this embodiment are basically corresponding to the embodiments, principles, and examples of the foregoing device, for the parts not described in detail in the description of this embodiment, reference may be made to the relevant descriptions in the foregoing embodiments and will not be elaborated here.

[0127] In summary, it is easy for those skilled in the art to understand that, without conflict, the above-mentioned advantageous ways can be freely combined and superimposed.

[0128] The above are only the embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the scope of the claims of the present invention.

Claims

1. A power-on surge protection device for a motor controller, characterized in that, The motor controller has three-phase AC power access terminals and a rectification unit; The anti-power-on surge protection device of the motor controller includes: A first protection unit connected between one of the three-phase AC power access terminals and the rectification unit; the first protection unit has a first current-limiting resistor module and a first switch module, and the first current-limiting resistor module and the first switch module are arranged in parallel; A second protection unit connected between another one of the three-phase AC power access terminals and the rectification unit; the second protection unit has a second current-limiting resistor module and a second switch module, and the second current-limiting resistor module and the second switch module are arranged in parallel; After the motor controller is powered on, both the first switch module and the second switch module are turned off, so that both the first current-limiting resistor module and the second current-limiting resistor module are connected; after a set time, both the first switch module and the second switch module are closed, so that both the first current-limiting resistor module and the second current-limiting resistor module are cut out.

2. The anti-power-on surge protection device for the motor controller according to claim 1, characterized in that, The three-phase AC power access terminals have a live wire L1, a live wire L2, and a live wire L3; The anti-power-on surge protection device further includes: A third protection unit having a first filtering module, a second filtering module, a third filtering module, and a discharge tube module; wherein, the first filtering module is connected between the live wire L1 and the discharge tube module; the second filtering module is connected between the live wire L2 and the discharge tube module; the third filtering module is connected between the live wire L3 and the discharge tube module; the discharge tube module is connected between the common end of the first filtering module, the second filtering module, and the third filtering module and the ground.

3. The anti-power-on surge protection device of the motor controller according to claim 2, wherein The first filtering module includes a first resistor module and a first capacitor module, and the first capacitor module is connected in parallel across the first resistor module; the second filtering module includes a second resistor module and a second capacitor module, and the second capacitor module is connected in parallel across the second resistor module; the third filtering module includes a third resistor module and a third capacitor module, and the third capacitor module is connected in parallel across the third resistor module.

4. The anti-power-on surge protection device for a motor controller according to any one of claims 1 to 3, characterized in that It further includes: A common-mode inductor unit, the input end of the common-mode inductor unit is connected to the three-phase AC power access terminals, and one phase of the output end of the common-mode inductor unit is connected to the first protection unit; another one of the output ends of the common-mode inductor unit is connected to the second protection unit.

5. The anti-power-on surge protection device of the motor controller according to claim 1, wherein The first current-limiting resistor module includes a first thermistor module, the second current-limiting resistor module includes a second thermistor module, the first switch module includes a first relay module, and the second switch module includes a second relay module; The first relay module has a coil and a normally open contact; the first thermistor module and the normally open contact of the first relay module are arranged in parallel; The second relay module has a coil and a normally open contact; the second thermistor module is arranged in parallel with the normally open contact of the second relay module.

6. The anti-power-on surge protection device for a motor controller according to claim 5, wherein The first protection unit further includes: a first diode module, the first diode module is connected in parallel across the two ends of the coil of the first relay module; the positive electrode of the first diode module is grounded, and the negative electrode of the first diode module is connected to a preset DC power supply; The second protection unit further includes: a second diode module, the second diode module is connected in parallel across the two ends of the coil of the second relay module; the positive electrode of the second diode module is grounded, and the negative electrode of the second diode module is connected to a preset DC power supply.

7. The anti-power-on surge protection device for a motor controller according to claim 6, wherein The first protection unit further includes: a fourth capacitor module and a fifth capacitor module; wherein, the fourth capacitor module is connected in parallel with the first diode module; the fifth capacitor module is connected in parallel with the second diode module.

8. A motor controller, characterized in that, Comprising: The anti-power-on surge protection device for a motor controller according to any one of claims 1 to 7.

9. A motor, characterized in that, Comprising: The anti-power-on surge protection device for a motor controller according to any one of claims 1 to 7, or the motor controller according to claim 8.

10. A method for protecting a motor controller against power-on surge corresponding to the power-on surge protection device of the motor controller according to any one of claims 1 to 7, characterized in that, Comprising: After the motor controller is powered on, control both the first switch module and the second switch module to be disconnected, so that both the first current-limiting resistor module and the second current-limiting resistor module are connected; After a set time, control both the first switch module and the second switch module to be closed, so that both the first current-limiting resistor module and the second current-limiting resistor module are cut out.

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