Bus voltage protection method, apparatus, compressor, and temperature regulating device

Abstract

The application provides a bus voltage protection method and device, a compressor and a temperature regulation device. The method comprises the following steps: obtaining a high-pressure value of the compressor, and determining whether the high-pressure value is less than or equal to a first pressure threshold value; if yes, controlling the compressor to perform gradual frequency regulation; and if no, controlling the compressor to stop and simultaneously controlling the compressor to perform braking energy consumption. According to the application, the compressor winding and the braking resistor can be prevented from heating, and the reliability of the compressor can be improved while avoiding the increase of the bus voltage value.

Description

Technical Field

[0001] This application relates to the field of electronic power technology, and in particular to a bus voltage protection method, device, compressor and temperature control equipment. Background Technology

[0002] When a high-speed compressor experiences a high-pressure anomaly during operation, it must be shut down quickly to prevent damage to the compressor itself. Drive circuits using bus capacitors with very small capacitance (such as film capacitors) cannot effectively absorb the regenerative braking energy generated by the rapid shutdown of the compressor, easily leading to a sudden increase in bus voltage and consequently damaging critical components such as the rectifier bridge.

[0003] To address the aforementioned issues, existing technologies typically involve directly controlling the compressor to perform regenerative braking, which consumes energy through the compressor windings or braking resistors. However, prolonged or frequent use can lead to overheating and damage to the compressor windings or braking resistors.

[0004] There is currently no effective solution to the problem that directly controlling the energy consumption of the compressor windings or braking resistor when the compressor experiences a high-pressure abnormality can easily lead to overheating and damage to the compressor windings or braking resistor, resulting in reduced reliability. Summary of the Invention

[0005] This application provides a bus voltage protection method, device, compressor, and temperature control equipment to solve the problem in the prior art that directly controlling the energy consumption of the compressor winding or braking resistor when the compressor experiences a high-pressure abnormality can easily lead to overheating and damage to the compressor winding or braking resistor, resulting in reduced reliability.

[0006] In a first aspect, this application provides a bus voltage protection method applied to a compressor, characterized in that the method includes: Obtain the high pressure value of the compressor and determine whether the high pressure value is less than or equal to a first pressure threshold. If so, control the compressor to perform progressive frequency adjustment; If not, then control the compressor to stop and simultaneously control the compressor to consume braking energy.

[0007] In one possible implementation, controlling the compressor to perform progressive frequency regulation includes: Determine the range in which the high-pressure value falls; If the high pressure value is less than or equal to the first pressure threshold and greater than the second pressure threshold, the frequency of the compressor is controlled to decrease. If the high pressure value is less than or equal to the second pressure threshold and greater than the third pressure threshold, the frequency of the compressor is controlled to remain unchanged. If the high pressure value is less than or equal to the third pressure threshold, the frequency of the compressor is controlled to increase. Wherein, the first pressure threshold > the second pressure threshold > the third pressure threshold.

[0008] In one possible implementation, reducing the frequency of controlling the compressor includes: Determine whether the high pressure value is less than a fourth pressure threshold; wherein the fourth pressure threshold is greater than the second pressure threshold and less than the first pressure threshold; If so, the frequency of the compressor is controlled to decrease at a first preset speed; If not, the frequency of the compressor is controlled to decrease at a second preset speed; wherein the second preset speed is greater than the first preset speed.

[0009] In one possible implementation, while controlling the compressor to perform progressive frequency regulation, the method further includes: Determine whether the DC bus voltage value is greater than the first voltage threshold. If so, the compressor is controlled to consume braking energy.

[0010] In one possible implementation, the compressor includes a capacitor drive circuit, which includes: a controllable switch with its control terminal connected to a controller and its output terminal connected to the negative terminal of a bus capacitor; a first braking resistor and a second braking resistor connected in series, the first braking resistor being connected to the positive terminal of the bus capacitor and the second braking resistor being connected to the input terminal of the controllable switch; and a switch connected in parallel with either the first or the second braking resistor. The control of the compressor to consume braking energy includes: The compressor is controlled to perform braking energy consumption based on the bus voltage value and the compressor winding temperature value.

[0011] In one possible implementation, controlling the compressor to perform braking energy consumption based on the bus voltage value and the compressor winding temperature value includes: Determine the range in which the bus voltage value falls; If the bus voltage value is greater than the first voltage threshold, the compressor is controlled to enter the corresponding braking energy consumption mode according to the compressor winding temperature value; wherein, the braking energy consumption mode includes: short circuit consumption mode and resistance consumption mode; If the bus voltage value is greater than the second voltage threshold, the compressor is directly controlled to enter the resistance consumption mode.

[0012] In one possible implementation, controlling the compressor to enter a corresponding braking energy consumption mode based on the compressor winding temperature value includes: Determine whether the compressor winding temperature is less than or equal to a first temperature threshold. If so, control the compressor to enter short-circuit consumption mode; If not, then control the compressor to enter the resistance consumption mode.

[0013] In one possible implementation, controlling the compressor to enter a short-circuit consumption mode includes: Determine whether the winding temperature value is less than a second temperature threshold; wherein the second temperature threshold is less than the first temperature threshold; If so, then control the compressor to perform a static short-circuit energy dissipation operation; If not, then control the compressor to perform dynamic short-circuit energy dissipation operation.

[0014] In one possible implementation, controlling the compressor to perform a static short-circuit energy dissipation operation includes: The lower bridge arm of the inverter module is fully turned on, and the upper bridge arm is fully turned off.

[0015] In one possible implementation, controlling the compressor to perform dynamic short-circuit energy dissipation operation includes: The lower bridge arm of the inverter module connected to the compressor is fully turned on, and the upper bridge arm is turned on according to a preset duty cycle, wherein the preset duty cycle is negatively correlated with the temperature value of the compressor winding.

[0016] In one possible implementation, controlling the compressor to enter a resistance consumption mode includes: Determine whether the motor power and the temperature of the first braking resistor when the compressor stops meet preset conditions; If so, the first braking resistor of the compressor is connected to perform single-resistor energy consumption operation; If not, the first and second braking resistors of the compressor are connected to perform dual-resistor energy consumption operation; The preset conditions are: the motor power when the compressor stops is less than the preset coefficient × the braking resistor power; and the temperature of the first braking resistor is less than or equal to the preset temperature.

[0017] Secondly, this application provides a capacitor driving circuit, the circuit comprising: A controllable switch, whose control terminal is connected to a controller and whose input terminal is connected to the negative terminal of a bus capacitor; A first braking resistor and a second braking resistor are connected in series. The first braking resistor is connected to the positive terminal of the bus capacitor, and the second braking resistor is connected to the output terminal of the controllable switch. The relay has its moving contact connected between the second braking resistor and the first braking resistor via an armature, its stationary contact connected between the second braking resistor and the positive terminal of the bus capacitor, its first end of its coil connected to a voltage source, and its second end of its coil grounded via a switching transistor. The bus capacitor is also connected to the compressor motor via an inverter module.

[0018] Thirdly, a protection device is provided for use in a compressor to implement the aforementioned bus voltage protection method. The device includes: The judgment module is used to obtain the high pressure value of the compressor and determine whether the high pressure value is less than or equal to a first pressure threshold. The first control module is used to control the compressor to perform progressive frequency adjustment when the high pressure value is less than or equal to the first pressure threshold. The second control module is used to control the compressor to stop when the high pressure value is greater than the first pressure threshold, and at the same time control the compressor to consume braking energy.

[0019] Fourthly, a compressor is provided, including a motor and a capacitor drive circuit, and also including the aforementioned protection device.

[0020] Fifthly, a temperature regulating device is provided, including the aforementioned compressor.

[0021] In a sixth aspect, this application provides an electronic device, comprising: a processor and a memory, wherein the processor is configured to execute a bus voltage protection program stored in the memory to implement the bus voltage protection method described in any one of the first aspects.

[0022] In a seventh aspect, this application provides a storage medium storing one or more programs that can be executed by one or more processors to implement the bus voltage protection method described in any one aspect.

[0023] Compared with the prior art, the technical solution provided in this application has the following advantages: The method provided in this application, when the high pressure value of the compressor is low, does not require rapid shutdown. By controlling the frequency reduction speed of the compressor, the compressor frequency is gradually reduced. While effectively controlling the high pressure value, the bus voltage value can be avoided. In addition, since no regenerative braking energy is generated during the frequency reduction process, there is no need to consume the regenerative braking energy through the compressor winding or braking resistor, which can avoid the compressor winding or braking resistor from overheating and damage, thus improving reliability. When the high pressure value of the compressor is high, only by controlling the compressor to stop quickly can the high pressure be effectively controlled. Regenerative braking energy is generated during the rapid shutdown of the compressor. By consuming the regenerative braking energy, it is ensured that the regenerative braking energy will not be fed back to the DC bus, thereby avoiding the bus voltage value from rising. Attached Figure Description

[0024] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0025] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0027] Figure 1 A flowchart illustrating a bus voltage protection method provided in this application embodiment; Figure 2 This is a structural diagram of a capacitor drive circuit for a compressor provided in an embodiment of the present invention; Figure 3 A flowchart illustrating another bus voltage control method provided in this application embodiment; Figure 4 A structural diagram of a capacitor drive circuit for another compressor provided in an embodiment of the present invention; Figure 5 A structural block diagram of a protection device provided in an embodiment of this application; Figure 6 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0029] The following disclosure provides numerous different embodiments or examples for implementing various structures of this application. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0030] To address the technical problem in existing technologies where direct control of the compressor windings or braking resistors to dissipate energy during high-pressure anomalies can easily lead to overheating damage of the compressor windings or braking resistors, thus reducing reliability, this application provides a bus voltage protection method. This method can effectively control high-pressure while preventing overheating damage to the compressor windings or braking resistors, thereby improving the operational reliability and stability of the compressor.

[0031] Example 1 Figure 1 This is a flowchart illustrating an embodiment of a bus voltage protection method provided in this application. Figure 1 As shown, the method includes the following steps: S101, obtain the high pressure value of the compressor and determine whether the high pressure value is less than or equal to the first pressure threshold; if yes, proceed to step S102; if no, proceed to step S103.

[0032] The high-pressure value of a compressor refers to the pressure of the gas at the compressor outlet after the compressor has compressed low-pressure gas to a certain pressure. This pressure value is crucial to the compressor's performance and efficiency because it directly affects the compressor's output power and energy efficiency ratio. Different ambient temperatures, humidity levels, altitudes, etc., all affect the compressor's high-pressure value. In existing technology, when the compressor's high-pressure value is too high, the compressor is controlled to shut down rapidly. During this process, the compressor's frequency decreases rapidly, generating regenerative braking energy. This regenerative braking energy is fed back to the bus, causing the bus voltage to increase.

[0033] S102 controls the compressor to perform gradual frequency adjustment.

[0034] When the compressor's high pressure value is low, there is no need to stop the machine quickly. The high pressure value can be effectively controlled by gradually reducing the compressor frequency. By setting the frequency reduction speed appropriately, regenerative braking energy will not be generated.

[0035] S103 controls the compressor to stop and simultaneously controls the compressor to consume braking energy.

[0036] When the compressor's high pressure value is high, only by controlling the compressor to stop quickly can the high pressure be effectively controlled. During the rapid shutdown of the compressor, regenerative braking energy is generated. By dissipating this regenerative braking energy, it is ensured that the regenerative braking energy is not fed back to the DC bus, thereby preventing the bus voltage value from rising. Therefore, at this time, controlling the compressor to dissipate braking energy prevents the bus voltage value from soaring due to direct shutdown at high speed, thus achieving a "soft stop" transition.

[0037] The bus voltage protection method of this embodiment does not require rapid shutdown when the compressor's high-pressure value is low. By controlling the compressor's frequency reduction rate, the compressor frequency is gradually reduced, effectively controlling the high-pressure value while preventing the bus voltage value from rising. In addition, since no regenerative braking energy is generated during the frequency reduction process, there is no need to consume the regenerative braking energy through the compressor windings or braking resistors, thus avoiding overheating and damage to the compressor windings or braking resistors and improving reliability. When the compressor's high-pressure value is high, only by controlling the compressor to stop rapidly can the high-pressure pressure be effectively controlled. Regenerative braking energy is generated during the rapid shutdown of the compressor. By consuming the regenerative braking energy, it is ensured that the regenerative braking energy is not fed back to the DC bus, thereby preventing the bus voltage value from rising.

[0038] Example 2 As mentioned above, when the compressor's high-pressure value is low, there is no need to quickly shut down the compressor; the high-pressure value can be effectively controlled by gradually reducing the compressor frequency. If the high-pressure value is less than or equal to a first pressure threshold, and it is greater than a second pressure threshold, it indicates a high high-pressure value, requiring a reduction in compressor frequency. If the high-pressure value is less than or equal to the second pressure threshold and greater than a third pressure threshold, it indicates a relatively low high-pressure value, not exceeding the high-pressure protection threshold, and the compressor frequency remains unchanged to avoid frequent start-stop cycles caused by repeated high-pressure fluctuations, thus improving system stability. If the high-pressure value is less than or equal to the third pressure threshold, it indicates a high-pressure value far below the high-pressure protection threshold, allowing the compressor frequency to be increased. Therefore, controlling the compressor to perform gradual frequency adjustment includes: determining the range of the high-pressure value; if the high-pressure value is less than or equal to the first pressure threshold and greater than the second pressure threshold, reducing the compressor frequency; if the high-pressure value is less than or equal to the second pressure threshold and greater than the third pressure threshold, maintaining the compressor frequency unchanged; and if the high-pressure value is less than or equal to the third pressure threshold, increasing the compressor frequency. Wherein, the first pressure threshold > the second pressure threshold > the third pressure threshold.

[0039] When the high-pressure value is less than or equal to the first pressure threshold and greater than the second pressure threshold, if the high-pressure value is high and exceeds a certain value between the first and second pressure thresholds, the compressor frequency should be reduced more quickly to ensure normal operation of the compressor. If the high-pressure value is low and does not exceed the aforementioned value, the frequency can be reduced at a smaller rate to avoid an increase in the bus voltage. Therefore, controlling the compressor frequency reduction specifically includes: determining whether the high-pressure value is less than the fourth pressure threshold; wherein the fourth pressure threshold is greater than the second pressure threshold and less than the first pressure threshold; if yes, the compressor frequency is reduced at a first preset rate; if no, the compressor frequency is reduced at a second preset rate; wherein the second preset rate is greater than the first preset rate; wherein the first preset rate can be limited to the frequency reduction rate when the q-axis current is at its minimum value Iq_min = 0A. By limiting the current, it is ensured that the back electromotive force is always lower than the bus voltage value during the motor speed reduction process, avoiding entering the power generation mode. This is suitable for cases where the bus capacitor value is small, and can reduce regenerative energy from the source.

[0040] During the gradual frequency adjustment of the compressor, the bus voltage may become too high. To solve this problem, while controlling the compressor to perform gradual frequency adjustment, the above method also includes: determining whether the DC bus voltage is greater than the first voltage threshold; if so, controlling the compressor to consume braking energy.

[0041] Figure 2This is a structural diagram of a capacitor drive circuit for a compressor provided in an embodiment of the present invention. The capacitor drive circuit includes: a controllable switch IGBT7, whose control terminal is connected to a controller 1, and whose output terminal is connected to the negative terminal of a bus capacitor C; a first braking resistor R1 and a second braking resistor R2 connected in series, the first braking resistor R1 being connected to the input terminal of the controllable switch IGBT7, and the second braking resistor R2 being connected to the positive terminal of the bus capacitor C; and a switch connected in parallel with either the first braking resistor R1 or the second braking resistor R2. In this embodiment, the switch is a relay K1, whose moving contact is connected between the second braking resistor R2 and the first braking resistor R1 via an armature, and whose stationary contact is connected between the second braking resistor R2 and the positive terminal of the bus capacitor C. The first end of its coil is connected to a voltage source, and the second end of its coil is grounded via a switching transistor Q1; the bus capacitor C is connected to the compressor motor M via an inverter module.

[0042] Braking energy consumption includes energy consumption through the compressor windings and energy consumption through the braking resistor. In order to avoid excessively high bus voltage or excessively high compressor winding temperature, the compressor is controlled to consume braking energy, including: controlling the compressor to consume braking energy based on the bus voltage and compressor winding temperature.

[0043] The braking energy consumption modes include short-circuit consumption mode and resistance consumption mode. Short-circuit consumption mode refers to consuming regenerative braking energy through the motor windings, while resistance consumption mode refers to consuming regenerative braking energy through the aforementioned braking resistor. Since the resistance of the braking resistor is greater than the resistance of the motor windings, the energy consumption rate in resistance consumption mode is faster than in short-circuit consumption mode. The higher the bus voltage, the faster the energy consumption mode needs to be. Therefore, to adapt the energy consumption rate to the bus voltage, the compressor is controlled to consume braking energy based on the bus voltage and compressor winding temperature. This includes: determining the range of the bus voltage; if the bus voltage is greater than a first voltage threshold, controlling the compressor to enter the corresponding braking energy consumption mode based on the winding temperature; where the braking energy consumption modes include short-circuit consumption mode and resistance consumption mode; if the bus voltage is greater than a second voltage threshold, directly controlling the compressor to enter the faster resistance consumption mode.

[0044] To prevent excessively high compressor winding temperatures and improve reliability, the compressor is controlled to enter the corresponding braking energy consumption mode based on the winding temperature. This includes: determining whether the winding temperature is less than or equal to a first temperature threshold; if so, controlling the compressor to enter a short-circuit consumption mode to consume regenerative braking energy through the compressor windings; if not, it indicates that the windings are approaching their limit temperature, and short-circuit braking will accelerate insulation aging. In this case, the compressor is controlled to enter a resistance consumption mode to consume regenerative braking energy through the braking resistor, and an external resistor is activated to prevent compressor damage.

[0045] The short-circuit energy dissipation mode includes static short-circuit energy dissipation operation and dynamic short-circuit energy dissipation operation. During dynamic short-circuit energy dissipation operation, the winding is intermittently conducting, so the temperature rises more slowly. Therefore, to avoid the compressor winding temperature from becoming too high, the compressor is controlled to enter the short-circuit energy dissipation mode, which includes: determining whether the winding temperature is less than a second temperature threshold; where the second temperature threshold is less than the first temperature threshold; if yes, the compressor is controlled to perform static short-circuit energy dissipation operation, that is, the lower bridge arm of the inverter module is fully turned on and the upper bridge arm is fully turned off. In this case, there are no external components, no need for braking resistors, energy saving and reliability, and the winding heat dissipation capacity is good; if no, the compressor is controlled to perform dynamic short-circuit energy dissipation operation, that is, the lower bridge arm of the inverter module connected to the compressor is fully turned on and the upper bridge arm is turned on according to a preset duty cycle. The preset duty cycle is negatively correlated with the winding temperature, and a dynamic balance mechanism is adopted: temperature ↑ → duty cycle ↓ → copper loss ↓ → avoid winding overheating, but inevitably some regenerative braking energy will be used to raise the bus voltage.

[0046] The resistance consumption mode includes single-resistor energy consumption operation and dual-resistor energy consumption operation. In dual-resistor energy consumption operation, the effective resistance is larger, and the energy consumption rate is faster. The higher the compressor's power and the higher the bus voltage when it stops, the faster the energy consumption rate needs to be. Furthermore, if the temperature of the first braking resistor is high, a second resistor needs to be connected to increase the energy consumption rate. Therefore, to ensure that the energy consumption rate is compatible with the compressor's power and the temperature of the first braking resistor, and to leave a margin for the braking resistor to avoid damage due to excessive power, the compressor is controlled to enter resistance consumption mode. This includes: determining whether the motor power and the temperature of the first braking resistor when the compressor stops meet preset conditions; if yes, controlling the first braking resistor of the compressor to connect and performing single-resistor energy consumption operation; if not, controlling both the first and second braking resistors of the compressor to connect and performing dual-resistor energy consumption operation. The preset conditions are: the motor power when the compressor stops < preset coefficient × braking resistor power; and the temperature of the first braking resistor ≤ preset temperature.

[0047] Example 3 This embodiment provides another method for controlling bus voltage. Figure 3 A flowchart of another bus voltage control method provided in the embodiments of this application is shown below. Figure 3 As shown, the method includes: S1. Detect the high-pressure value of the compressor and determine the range within which the high-pressure value falls. If the high-pressure value is less than the first preset pressure (e.g., 14.5 MPa), proceed to step S2. If the first preset pressure (e.g., 14.5 MPa) is less than the high-pressure value and less than or equal to the second preset pressure (15 MPa), proceed to step S3. If the second preset pressure (e.g., 15 MPa) is less than the high-pressure value and less than or equal to the third preset pressure (e.g., 16 kPa), proceed to step S4. If the third preset pressure (e.g., 16 kPa) is less than the high-pressure value and less than or equal to the fourth preset pressure (e.g., 17 kPa), proceed to step S5. If the high-pressure value is greater than or equal to the fourth preset pressure (e.g., 17 kPa), proceed to step S6. The first preset pressure corresponds to the third pressure threshold in the above embodiment, the second preset pressure corresponds to the second pressure threshold in the above embodiment, the third preset pressure corresponds to the fourth pressure threshold in the above embodiment, and the fourth preset pressure corresponds to the first pressure threshold in the above embodiment.

[0048] S2 controls the compressor frequency to increase.

[0049] A high pressure value less than the first preset pressure (e.g., 14.5 MPa) indicates that the high pressure value is far below the high pressure protection threshold, which can control the compressor frequency increase.

[0050] S3 controls the compressor frequency to remain constant.

[0051] There is a certain safety margin between the first preset pressure (e.g., 14.5 MPa) and the second preset pressure (15 MPa) (high pressure protection threshold), which can avoid frequent start-stop caused by repeated fluctuations in high pressure and improve system stability.

[0052] S4, control the compressor frequency to decrease according to the first preset speed.

[0053] S5 controls the compressor frequency to decrease according to the second preset speed.

[0054] The first preset speed can be limited to the frequency reduction speed when the minimum q-axis current Iq_min=0A. By limiting the current, it is ensured that the back electromotive force is always lower than the bus voltage value during the motor speed reduction process, thus avoiding entering the power generation mode. This is suitable for situations where the bus capacitor value is small, and can reduce regenerative energy from the source.

[0055] The second preset speed is greater than the first preset speed below. Controlling the compressor frequency to decrease according to the second preset speed can shorten the high-pressure exposure time of the compressor, improve the system response speed, and prevent the high pressure from continuing to rise.

[0056] S6 controls the compressor to stop and simultaneously controls the compressor to consume braking energy.

[0057] S7, determine the range of the bus voltage; if the bus voltage ≤ V1, return to step S1; if V1 < bus voltage ≤ V2, execute step S8; if the bus voltage > V2, execute step S11.

[0058] S8, calculate the compressor winding temperature; if the compressor winding temperature < T2, then proceed to step S9; if T2 < compressor winding temperature ≤ T1, then proceed to step S10; if the compressor winding temperature > T1, then proceed to step S11.

[0059] Where T1 > T2.

[0060] S9 controls the compressor to consume energy during a static short circuit.

[0061] S10 controls the compressor to perform dynamic short-circuit energy consumption.

[0062] S11, calculate the power of the compressor when it stops and the temperature of the first braking resistor R1.

[0063] S12, determine whether the compressor power < 1.5 × the power of the first specified resistor R1, and the temperature of the first specified resistor R1 ≤ derating temperature; if yes, proceed to step S13; if no, proceed to step S14.

[0064] S13 controls the compressor to consume energy using a single resistor.

[0065] S14 controls the compressor to consume energy using dual resistance.

[0066] The bus voltage protection method in this embodiment includes the following two core components: 1. High-pressure progressive frequency regulation control of the compressor During frequency modulation, if the high pressure value exceeds the fourth preset pressure (e.g., 17MPa), the system will immediately shut down the PWM output and activate the regenerative braking energy consumption mechanism.

[0067] If, during frequency adjustment, the compressor's high-pressure value does not exceed the fourth preset pressure (e.g., 17 MPa) but exceeds the third preset pressure (e.g., 16 MPa), the system will start the first frequency reduction speed.

[0068] If the compressor's high-pressure value does not exceed the third preset pressure (e.g., 16 MPa) but exceeds the second preset pressure (e.g., 15 MPa), the system initiates a second frequency reduction rate, decreasing the reduction rate to half of the first frequency reduction rate (e.g., increasing from 4 Hz / s to 2 Hz / s), performing frequency regulation control at the maximum frequency reduction rate without generating regenerative braking. This rate is achieved by setting the minimum q-axis current to zero (Iq_min = 0 A) to avoid energy feedback.

[0069] If the compressor's high-pressure value does not exceed the second preset pressure (e.g., 15 MPa), but exceeds the first preset pressure (e.g., 14.5 MPa), the compressor is controlled to maintain the current frequency.

[0070] If, during frequency adjustment, the compressor's high-pressure pressure is lower than the first preset pressure (e.g., 14.5 MPa), which is the second preset pressure minus a certain safety margin, the system will allow the frequency to gradually increase at a rate of 1 Hz / s.

[0071] 2. Regenerative braking energy processing (triggered when bus voltage > V1) - During frequency reduction or shutdown, if the bus voltage exceeds the preset threshold V1 (e.g., V1 = maximum withstand voltage of the device - 200V), the system activates the regenerative braking protection mechanism. The controller calculates the motor power based on the sampled current and bus voltage, and then, combined with the compressor surface temperature, uses the junction temperature and case temperature formula T... j =T h +p×θ jh Calculate the current compressor winding temperature and select either short-circuit energy consumption or dynamic short-circuit energy consumption, where T j T represents the winding temperature (°C). h The compressor casing surface temperature (°C), i.e., the compressor winding temperature, is sampled; P is the total power consumption of the compressor (W, i.e., the motor power when the compressor is off); θ jh Thermal resistance from compressor windings to housing (°C / W, provided by the manufacturer).

[0072] If the winding temperature is lower than T2 (T2 is the compressor winding limit temperature -40℃), the system performs static short-circuit energy dissipation: the upper bridge arm IGBT is fully turned off and the lower bridge arm IGBT is fully turned on, so that the motor winding forms a closed loop, and the regenerative braking energy is dissipated in the form of winding heat.

[0073] When the winding temperature is between T2 and T1 (T1 is the compressor winding's maximum temperature of -20℃), the system employs a dynamic short-circuit energy dissipation strategy. The duty cycle of the upper arm IGBT is dynamically adjusted based on the current temperature, calculated as (T2-T) / (T2-T1)%, with the lower arm IGBT fully open. Lower winding temperatures result in higher duty cycles and greater copper losses; higher temperatures lead to lower duty cycles and reduced copper losses. In other words, part of the regenerative braking energy is used for winding heating, and part is used to forcibly raise the bus voltage.

[0074] When the winding temperature reaches or exceeds T1, or the bus voltage exceeds V2 (e.g., V2 = maximum withstand voltage of the device - 100V), the system switches to the braking resistor energy consumption mode: PWM output is turned off, IGBT7 is turned on, and the controller calculates the power consumption when the motor shuts down based on the sampled current and bus voltage. This calculation is then combined with the surface temperature of the braking resistor R1, using the junction temperature and case temperature formula T... j =T c +p×θ jc Calculate the junction temperature T of the current braking resistor R1. j Junction temperature (°C); T c The case temperature (°C) is the temperature of the resistor sample, P is the power consumption of the device (W), i.e., the power of the resistor, and θ is the resistance temperature. jc The junction-to-case thermal resistance (°C / W) is provided by the manufacturer. Choose to connect either the first braking resistor R1 or the first braking resistor R1 and the second braking resistor R2 (two medium-sized braking resistors are cheaper than large-sized ones, but connecting two resistors directly will reduce their lifespan, so connect one when not needed and two when needed) to consume regenerative braking energy.

[0075] When the power is less than 1.5 times the power of the first braking resistor R1 and the temperature of the braking resistor R1 is below the derating temperature, the system enters the single-resistor energy consumption mode, and connects to R1 through IGBT7 to meet the low-power braking requirements.

[0076] When the power supply is turned off, if the power consumption reaches or exceeds 1.5 times the power of the braking resistor R1, or if the temperature of the braking resistor R1 reaches or exceeds the derating temperature (the resistor power decreases after exceeding the derating temperature), the system will activate the dual-resistor energy consumption mode. The controller sends a high-level signal to drive transistor Q1 to conduct, which in turn energizes relay K1 and opens its normally closed contact. At this time, R1 and R2 are connected in series in the braking circuit to increase braking energy consumption.

[0077] In this application, the first priority is to ensure the operation of the unit, so the frequency is reduced first. Short-circuit energy consumption does not require a braking resistor, because the energy consumption braking of the braking resistor may damage the braking resistor. Therefore, the braking resistor is used as a last resort.

[0078] For ease of understanding, the following table summarizes the findings: 1. High-pressure progressive frequency regulation control of the compressor By triggering different frequency reduction strategies using multi-level high-voltage thresholds, direct shutdown at high speeds is avoided, thus suppressing sudden increases in bus voltage from the source.

[0079]

[0080] 2. Regenerative braking energy consumption (triggered when bus voltage > V1 or high voltage pressure > fourth preset pressure) When the bus voltage rises during frequency reduction or shutdown, the system initiates regenerative braking and dynamically selects the optimal energy consumption mode based on the bus voltage and compressor temperature.

[0081]

[0082] The technical solution provided in this application proposes a compressor high-pressure progressive frequency reduction control strategy to reduce the compressor high pressure while minimizing the probability of excessively high drive board bus voltage. It also proposes a dynamic decision-making mechanism based on bus voltage, current, compressor winding temperature, and braking resistor temperature to consume regenerative braking energy and reduce the probability of damage to the compressor winding and braking resistor.

[0083] Example 4 This embodiment provides a capacitor driving circuit, as mentioned above. Figure 2 As shown, the capacitor drive circuit includes: a controllable switch IGBT 7, whose control terminal is connected to the controller 1, and whose output terminal is connected to the negative terminal of the bus capacitor C; a first braking resistor R1 and a second braking resistor R2 connected in series, the first braking resistor R1 being connected to the input terminal of the controllable switch IGBT 7, and the second braking resistor R2 being connected to the positive terminal of the bus capacitor C; and a switch connected in parallel with either the first braking resistor R1 or the second braking resistor R2. In this embodiment, the switch is a relay K1, whose moving contact is connected between the second braking resistor R2 and the first braking resistor R1 via an armature, and whose stationary contact is connected between the second braking resistor R2 and the positive terminal of the bus capacitor C. The first end of its coil is connected to a voltage source, and the second end of its coil is grounded via a switching transistor Q1; the bus capacitor C is connected to the compressor motor M via an inverter module.

[0084] Figure 4 A structural diagram of another capacitor drive circuit for a compressor provided in an embodiment of the present invention is shown below. Figure 4As shown, this embodiment uses a three-phase inverter module as an example. The inverter module includes six bridge arm switches: three upper bridge arm switches (IGBT1, IGBT3, and IGBT5) and three lower bridge arm switches (IGBT2, IGBT4, and IGBT6). To obtain the bus voltage value, a voltage sampling module 40 is included. To obtain the compressor winding temperature value, a compressor temperature sampling module 50 is included. To obtain the motor current, and thus the aforementioned q-axis current, a current sampling module 60 is included, which includes an operational amplifier U1. To obtain the temperature of the first braking resistor R1, a resistor temperature sampling module 70 is included. To obtain the aforementioned high-pressure value, a compressor high-pressure sampling module 80 is included. Furthermore, to prevent current from directly flowing through the controllable switch IGBT7, and to allow the current to pass through the first braking resistor R1 and the second braking resistor R2, a diode D is included, with its anode connected between the second braking resistor R2 and the output terminal of the controllable switch IGBT7. After rectification by the rectifier, the mains power charges the bus capacitor C.

[0085] Example 5 This embodiment provides a protection device applied to a compressor, used to implement the bus voltage protection method described in the above embodiments. Figure 5 A structural block diagram of a protection device provided in an embodiment of this application is shown below. Figure 5 As shown, the protective device includes: The judgment module 10 is used to obtain the high pressure value of the compressor and determine whether the high pressure value is less than or equal to the first pressure threshold.

[0086] The high-pressure value of a compressor refers to the pressure of the gas at the compressor outlet after the compressor has compressed low-pressure gas to a certain pressure. This pressure value is crucial to the compressor's performance and efficiency because it directly affects the compressor's output power and energy efficiency ratio. Different ambient temperatures, humidity levels, altitudes, etc., all affect the compressor's high-pressure value. In existing technology, when the compressor's high-pressure value is too high, the compressor is controlled to shut down rapidly. During this process, the compressor's frequency decreases rapidly, generating regenerative braking energy. This regenerative braking energy is fed back to the bus, causing the bus voltage to increase.

[0087] The first control module 20 is used to control the compressor to perform progressive frequency adjustment when the high pressure value is less than or equal to the first pressure threshold.

[0088] When the compressor's high pressure value is low, there is no need to stop the machine quickly. The high pressure value can be effectively controlled by gradually reducing the compressor frequency. By setting the frequency reduction speed appropriately, regenerative braking energy will not be generated.

[0089] The second control module 30 is used to control the compressor to stop when the high pressure value is greater than the first pressure threshold, and at the same time control the compressor to consume braking energy.

[0090] When the compressor's high pressure value is high, only by controlling the compressor to stop quickly can the high pressure be effectively controlled. During the rapid shutdown of the compressor, regenerative braking energy is generated. By dissipating this regenerative braking energy, it is ensured that the regenerative braking energy is not fed back to the DC bus, thereby preventing the bus voltage value from rising. Therefore, at this time, controlling the compressor to dissipate braking energy prevents the bus voltage value from soaring due to direct shutdown at high speed, thus achieving a "soft stop" transition.

[0091] The protection device in this embodiment does not require rapid shutdown when the compressor's high pressure value is low. By controlling the compressor's frequency reduction speed, the compressor frequency is gradually reduced. This effectively controls the high pressure value while preventing the bus voltage value from rising. Furthermore, since no regenerative braking energy is generated during the frequency reduction process, there is no need to consume regenerative braking energy through the compressor windings or braking resistors, thus preventing overheating and damage to the compressor windings or braking resistors and improving reliability. When the compressor's high pressure value is high, only by controlling the compressor to quickly shut down can the high pressure be effectively controlled. Regenerative braking energy is generated during the rapid shutdown process. By consuming this regenerative braking energy, it is ensured that the regenerative braking energy is not fed back to the DC bus, thereby preventing the bus voltage value from rising.

[0092] As mentioned above, when the compressor's high-pressure value is low, there is no need to quickly shut down the compressor; the high-pressure value can be effectively controlled by gradually reducing the compressor frequency. If the high-pressure value is less than or equal to a first pressure threshold, and is greater than a second pressure threshold, it indicates a high high-pressure value, requiring a reduction in compressor frequency. If the high-pressure value is less than or equal to the second pressure threshold and greater than a third pressure threshold, it indicates that the high-pressure value is not high and has not exceeded the high-pressure protection threshold; therefore, the compressor frequency remains unchanged to avoid frequent start-stop cycles caused by repeated fluctuations in high-pressure value, thus improving system stability. If the high-pressure value is less than or equal to the third pressure threshold, it indicates that the high-pressure value is far below the high-pressure protection threshold, allowing the compressor frequency to be increased. Therefore, the first control module 20 is specifically used to: determine the range of the high-pressure value; if the high-pressure value is less than or equal to the first pressure threshold and greater than the second pressure threshold, control the compressor frequency to decrease; if the high-pressure value is less than or equal to the second pressure threshold and greater than the third pressure threshold, control the compressor frequency to remain unchanged; and if the high-pressure value is less than or equal to the third pressure threshold, control the compressor frequency to increase.

[0093] When the high-pressure value is less than or equal to the first pressure threshold and greater than the second pressure threshold, if the high-pressure value is high and exceeds a certain value between the first and second pressure thresholds, the compressor frequency should be reduced more quickly to ensure normal operation. If the high-pressure value is low and does not exceed the aforementioned value, the frequency can be reduced at a smaller rate to avoid an increase in the bus voltage. Therefore, controlling the compressor frequency reduction specifically includes: determining whether the high-pressure value is less than the fourth pressure threshold; wherein the fourth pressure threshold is greater than the second pressure threshold and less than the first pressure threshold; if so, the compressor frequency is reduced at a first preset rate; if not, the compressor frequency is reduced at a second preset rate; wherein the second preset rate is greater than the first preset rate. The first preset rate can be limited to the frequency reduction rate when the q-axis current is at its minimum value Iq_min = 0A. By limiting the current, it is ensured that the back electromotive force remains lower than the bus voltage during the motor speed reduction process, preventing the motor from entering the power generation mode. This is suitable for cases where the bus capacitor has a small capacitance value, thus reducing regenerative energy at the source.

[0094] During the process of the compressor performing gradual frequency adjustment, the bus voltage value may also occur. While controlling the compressor to perform gradual frequency adjustment, the first control module 20 is also used to: determine whether the DC bus voltage value is greater than the first voltage threshold; if so, control the compressor to consume braking energy.

[0095] As mentioned above Figure 2As shown, the capacitor drive circuit of the compressor includes: a controllable switch IGBT7, whose control terminal is connected to the controller 1 and whose output terminal is connected to the negative terminal of the bus capacitor C; a first braking resistor R1 and a second braking resistor R2 connected in series, the first braking resistor R1 being connected to the input terminal of the controllable switch IGBT7 and the second braking resistor R2 being connected to the positive terminal of the bus capacitor C; and a switch connected in parallel with either the first braking resistor R1 or the second braking resistor R2. In this embodiment, the switch is a relay K1, connected in parallel across the second braking resistor R2. The bus capacitor C is connected to the compressor motor via the inverter module. This embodiment uses a three-phase inverter module as an example. The inverter module includes six bridge arm switches: three upper bridge arm switches IGBT1, IGBT3, and IGBT5, and three lower bridge arm switches IGBT2, IGBT4, and IGBT6. A voltage sampling module 40 is included to obtain the bus voltage value. A compressor temperature sampling module 50 is included to obtain the compressor winding temperature value. A current sampling module 60 is included to obtain the motor current and thus the q-axis current, including an operational amplifier U1. A resistance temperature sampling module 70 is included to obtain the temperature of the first braking resistor R1. A compressor high-pressure sampling module 80 is included to obtain the high-pressure value. Furthermore, to prevent current from directly flowing through the controllable switch IGBT7 and instead allow the current to pass through the first braking resistor R1 and the second braking resistor R2, a diode D is included, with its anode connected between the second braking resistor R2 and the output terminal of the controllable switch IGBT7. After being rectified by the rectifier, the mains power charges the bus capacitor C.

[0096] Braking energy consumption includes energy consumption through the compressor windings and energy consumption through the braking resistor. In order to avoid the bus voltage value being too high or the temperature of the compressor windings being too high, the second control module 30 is specifically used to control the compressor to consume braking energy based on the bus voltage value and the temperature value of the compressor windings.

[0097] The braking energy consumption modes include: short-circuit consumption mode and resistance consumption mode. Short-circuit consumption mode refers to consuming regenerative braking energy through the motor windings, while resistance consumption mode refers to consuming regenerative braking energy through the aforementioned braking resistor. Since the resistance of the braking resistor is greater than the resistance of the motor windings, the energy consumption rate in resistance consumption mode is faster than in short-circuit consumption mode. The higher the bus voltage, the faster the energy consumption mode needs to be. Therefore, to adapt the energy consumption rate to the bus voltage value, the second control module 30 is further specifically used to: determine the range of the bus voltage value; if the bus voltage value is greater than the first voltage threshold, control the compressor to enter the corresponding braking energy consumption mode based on the winding temperature value; wherein, the braking energy consumption modes include: short-circuit consumption mode and resistance consumption mode; if the bus voltage value is greater than the second voltage threshold, directly control the compressor to enter the faster resistance consumption mode.

[0098] To prevent the compressor winding temperature from becoming too high and to improve reliability, the second control module 30 is further specifically used to: determine whether the winding temperature is less than or equal to the first temperature threshold; if so, control the compressor to enter the short-circuit consumption mode, and consume regenerative braking energy through the compressor winding; if not, it indicates that the compressor winding is close to the limit temperature, and short-circuit braking will accelerate insulation aging. At this time, control the compressor to enter the resistance consumption mode, consume regenerative braking energy through the braking resistor, and activate the external resistor to avoid compressor damage.

[0099] The short-circuit energy dissipation mode includes static short-circuit energy dissipation operation and dynamic short-circuit energy dissipation operation. During dynamic short-circuit energy dissipation operation, the winding is intermittently conducting, so the temperature rises more slowly. Therefore, to avoid the compressor winding temperature from becoming too high, the compressor is controlled to enter the short-circuit energy dissipation mode, which includes: determining whether the winding temperature is less than a second temperature threshold; where the second temperature threshold is less than the first temperature threshold; if yes, the compressor is controlled to perform static short-circuit energy dissipation operation, that is, the lower bridge arm of the inverter module is fully turned on and the upper bridge arm is fully turned off. In this case, there are no external components, no need for braking resistors, energy saving and reliability, and the winding heat dissipation capacity is good; if no, the compressor is controlled to perform dynamic short-circuit energy dissipation operation, that is, the lower bridge arm of the inverter module connected to the compressor is fully turned on and the upper bridge arm is turned on according to a preset duty cycle. The preset duty cycle is negatively correlated with the winding temperature, and a dynamic balance mechanism is adopted: temperature ↑ → duty cycle ↓ → copper loss ↓ → avoid winding overheating, but inevitably some regenerative braking energy will be used to raise the bus voltage.

[0100] The resistance consumption mode includes single-resistor energy consumption operation and dual-resistor energy consumption operation. In dual-resistor energy consumption operation, the effective resistance is larger, and the energy consumption rate is faster. The higher the power of the compressor when it stops, the higher the bus voltage, and the faster the energy consumption rate needs to be. Furthermore, if the temperature of the first braking resistor is high, a second resistor needs to be connected to increase the energy consumption rate. Therefore, to ensure that the energy consumption rate is adapted to the compressor power and the temperature of the first braking resistor, and to leave a margin for the braking resistor to avoid damage due to excessive power, the second control module 30 is further specifically used to: determine whether the motor power and the temperature of the first braking resistor when the compressor stops meet preset conditions; if yes, control the first braking resistor of the compressor to be connected to perform single-resistor energy consumption operation; if no, control the first and second braking resistors of the compressor to be connected to perform dual-resistor energy consumption operation. The preset conditions are: motor power when the compressor stops < preset coefficient × braking resistor power; and the temperature of the first braking resistor ≤ preset temperature.

[0101] Example 6 This embodiment provides a compressor, including a motor and a capacitor drive circuit, and also includes the protection device described in the above embodiment.

[0102] Example 7 This embodiment provides a temperature regulating device, including the compressor described in the above embodiment. The temperature regulating device can be an air conditioner or a refrigerator.

[0103] Example 8 This embodiment provides an electronic device, characterized in that it includes a processor and a memory, wherein the processor is used to execute a bus voltage protection program stored in the memory to implement the bus voltage protection method of the above embodiment.

[0104] Figure 6 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application, such as... Figure 6 As shown in the figure, this application provides a device including a processor 111, a communication interface 112, a memory 113, and a communication bus 114, wherein the processor 111, the communication interface 112, and the memory 113 communicate with each other through the communication bus 114. Memory 113 is used to store computer programs; In one embodiment of this application, the processor 111, when executing the program stored in the memory 113, implements the bus voltage protection method provided in any of the foregoing method embodiments.

[0105] Example 9 This application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the bus voltage protection method provided in any of the foregoing method embodiments.

[0106] The device embodiments described above are merely illustrative. The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0107] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented using software plus a general-purpose hardware platform, or of course, using hardware. Based on this understanding, the above technical solutions, in essence or the parts that contribute to the related technology, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0108] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0109] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A bus voltage protection method, applied to a compressor, characterized in that, The method includes: Obtain the high pressure value of the compressor and determine whether the high pressure value is less than or equal to a first pressure threshold. If so, control the compressor to perform progressive frequency adjustment; If not, then control the compressor to stop and simultaneously control the compressor to consume braking energy.

2. The method according to claim 1, characterized in that, The control of the compressor to perform progressive frequency adjustment includes: Determine the range in which the high-pressure value falls; If the high pressure value is less than or equal to the first pressure threshold and greater than the second pressure threshold, the frequency of the compressor is controlled to decrease. If the high pressure value is less than or equal to the second pressure threshold and greater than the third pressure threshold, the frequency of the compressor is controlled to remain unchanged. If the high pressure value is less than or equal to the third pressure threshold, the frequency of the compressor is controlled to increase. Wherein, the first pressure threshold > the second pressure threshold > the third pressure threshold.

3. The method according to claim 2, characterized in that, The reduction of the compressor frequency includes: Determine whether the high pressure value is less than a fourth pressure threshold; wherein the fourth pressure threshold is greater than the second pressure threshold and less than the first pressure threshold; If so, the frequency of the compressor is controlled to decrease at a first preset speed; If not, the frequency of the compressor is controlled to decrease at a second preset speed; wherein the second preset speed is greater than the first preset speed.

4. The method according to claim 1, characterized in that, While controlling the compressor to perform progressive frequency regulation, the method further includes: Determine whether the DC bus voltage value is greater than the first voltage threshold. If so, the compressor is controlled to consume braking energy.

5. The method according to claim 1, characterized in that, The compressor includes a capacitor drive circuit, which includes: a controllable switch, the control terminal of which is connected to a controller and the output terminal of which is connected to the negative terminal of a bus capacitor; a first braking resistor and a second braking resistor connected in series, the first braking resistor being connected to the positive terminal of the bus capacitor and the second braking resistor being connected to the input terminal of the controllable switch; and a switch connected in parallel with either the first or the second braking resistor. The control of the compressor to consume braking energy includes: The compressor is controlled to perform braking energy consumption based on the bus voltage value and the compressor winding temperature value.

6. The method according to claim 5, characterized in that, The step of controlling the compressor to perform braking energy consumption based on the bus voltage value and the compressor winding temperature value includes: Determine the range in which the bus voltage value falls; If the bus voltage value is greater than the first voltage threshold, the compressor is controlled to enter the corresponding braking energy consumption mode according to the compressor winding temperature value; wherein, the braking energy consumption mode includes: short circuit consumption mode and resistance consumption mode; If the bus voltage value is greater than the second voltage threshold, the compressor is directly controlled to enter the resistance consumption mode.

7. The method according to claim 6, characterized in that, The step of controlling the compressor to enter the corresponding braking energy consumption mode based on the compressor winding temperature value includes: Determine whether the compressor winding temperature is less than or equal to a first temperature threshold. If so, control the compressor to enter short-circuit consumption mode; If not, then control the compressor to enter the resistance consumption mode.

8. The method according to claim 6 or 7, characterized in that, Controlling the compressor to enter short-circuit consumption mode includes: Determine whether the winding temperature value is less than a second temperature threshold; wherein the second temperature threshold is less than the first temperature threshold; If so, then control the compressor to perform a static short-circuit energy dissipation operation; If not, then control the compressor to perform dynamic short-circuit energy dissipation operation.

9. The method according to claim 8, characterized in that, The control of the compressor to perform static short-circuit energy dissipation operation includes: The lower bridge arm of the inverter module is fully turned on, and the upper bridge arm is fully turned off.

10. The method according to claim 8, characterized in that, The control of the compressor to perform dynamic short-circuit energy dissipation operation includes: The lower bridge arm of the inverter module connected to the compressor is fully turned on, and the upper bridge arm is turned on according to a preset duty cycle, wherein the preset duty cycle is negatively correlated with the temperature value of the compressor winding.

11. The method according to claim 6 or 7, characterized in that, Controlling the compressor to enter resistance consumption mode includes: Determine whether the motor power and the temperature of the first braking resistor when the compressor stops meet preset conditions; If so, the first braking resistor of the compressor is connected to perform single-resistor energy consumption operation; If not, the first and second braking resistors of the compressor are connected to perform dual-resistor energy consumption operation; The preset conditions are: the motor power when the compressor stops is less than the preset coefficient × the braking resistor power; and the temperature of the first braking resistor is less than or equal to the preset temperature.

12. A capacitor driving circuit, characterized in that, The circuit includes: A controllable switch, whose control terminal is connected to a controller and whose output terminal is connected to the negative terminal of a bus capacitor; A first braking resistor and a second braking resistor are connected in series. The first braking resistor is connected to the positive terminal of the bus capacitor, and the second braking resistor is connected to the input terminal of the controllable switch. The switch is connected in parallel with either the first or the second braking resistor. The bus capacitor is also connected to the compressor motor via an inverter module.

13. A protection device applied to a compressor for implementing the bus voltage protection method according to any one of claims 1 to 11, characterized in that, The device includes: The judgment module is used to obtain the high pressure value of the compressor and determine whether the high pressure value is less than or equal to a first pressure threshold. The first control module is used to control the compressor to perform progressive frequency adjustment when the high pressure value is less than or equal to the first pressure threshold. The second control module is used to control the compressor to stop when the high pressure value is greater than the first pressure threshold, and at the same time control the compressor to consume braking energy.

14. A compressor, comprising a motor and a capacitor drive circuit, characterized in that, It also includes the protective device as described in claim 13.

15. A temperature regulating device, characterized in that, Includes the compressor as described in claim 14.

16. An electronic device, characterized in that, include: A processor and a memory, the processor being configured to execute a bus voltage value protection program stored in the memory to implement the bus voltage protection method according to any one of claims 1-11.

17. A storage medium, characterized in that, The storage medium stores one or more programs, which can be executed by one or more processors to implement the bus voltage protection method according to any one of claims 1-11.

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