CN112072904A

CN112072904A - Direct-current bus protection device, electrical equipment and direct-current bus protection method thereof

Info

Publication number: CN112072904A
Application number: CN202010885997.9A
Authority: CN
Inventors: 黄伟; 贺小林; 刘涛; 宋政璋
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2020-08-28
Filing date: 2020-08-28
Publication date: 2020-12-11

Abstract

The invention discloses a direct current bus protection device, electrical equipment and a direct current bus protection method thereof, wherein the device comprises: an energy releasing unit and/or an energy absorbing unit; the energy release unit is configured to release the spike pulse voltage on the direct current bus under the condition that the spike pulse voltage on the direct current bus is greater than or equal to a first set voltage and smaller than a second set voltage; the energy absorption unit is configured to absorb the spike pulse voltage on the direct current bus under the condition that the spike pulse voltage on the direct current bus is greater than or equal to a second set voltage. The scheme of the invention can solve the problem that the components are damaged by instantaneous impact or instantaneous high voltage when the electrolytic capacitor is replaced by the thin-film capacitor in the motor driving circuit, thereby achieving the effect of avoiding the components from being damaged by the instantaneous impact or the instantaneous high voltage.

Description

Direct-current bus protection device, electrical equipment and direct-current bus protection method thereof

Technical Field

The invention belongs to the technical field of motors, and particularly relates to a direct-current bus protection device, electrical equipment and a direct-current bus protection method thereof, in particular to a direct-current bus protection circuit of an air conditioning system, the air conditioning system and the direct-current bus protection method thereof.

Background

In a motor driving circuit, after an electrolytic capacitor with a large capacitance value is replaced by a thin film capacitor with a small capacitance value, voltage fluctuation is large, and components can be damaged by instantaneous impact or instantaneous high voltage.

The above is only for the purpose of assisting understanding of the technical aspects of the present invention, and does not represent an admission that the above is prior art.

Disclosure of Invention

The invention aims to provide a direct-current bus protection device, electrical equipment and a direct-current bus protection method thereof, which are used for solving the problem that components are damaged by instantaneous impact or instantaneous high voltage when an electrolytic capacitor is replaced by a thin-film capacitor in a motor driving circuit and achieving the effect of avoiding the components from being damaged by the instantaneous impact or the instantaneous high voltage.

The invention provides a direct current bus protection device, comprising: a bus protection unit; the bus protection unit is arranged on a direct current bus between a film capacitor and a bus capacitor in a power supply of the electrical equipment; the bus bar protection unit includes: an energy releasing unit and/or an energy absorbing unit; the energy release unit is configured to release the spike pulse voltage on the direct current bus under the condition that the spike pulse voltage on the direct current bus is greater than or equal to a first set voltage and smaller than a second set voltage; the energy absorption unit is configured to absorb the spike pulse voltage on the direct current bus when the spike pulse voltage on the direct current bus is greater than or equal to a second set voltage.

In some embodiments, further comprising: a sampling unit and a control unit; the sampling unit is configured to detect spike pulse voltage on the direct current bus; the control unit configured to determine a relationship between the detected spike voltage and a first set voltage and a second set voltage; if the detected spike pulse voltage is greater than or equal to a first set voltage and less than a second set voltage, controlling the energy release unit to be started; and if the detected spike pulse voltage is greater than or equal to a second set voltage, controlling the energy absorption unit to be started.

In some embodiments, the energy release unit comprises: a one-way module, a consumption module and a buffer module; wherein the unidirectional module is configured to control a release direction of the spike voltage; the consumption module is configured to consume the spike pulse voltage in a release direction of the spike pulse voltage; the buffer module is configured to store and buffer the spike voltage in a release direction of the spike voltage.

In some embodiments, the unidirectional module comprises: a diode module; the consumable module, comprising: a consumption resistance; the buffer module comprises: a buffer capacitor; wherein the anode of the diode module is connected to the positive pole of the direct current bus; and the cathode of the diode module is connected to the cathode of the direct current bus after passing through the consumption resistor and the buffer capacitor.

In some embodiments, the energy absorbing unit comprises: an absorption module and a safety module; wherein the absorption module is configured to absorb the spike voltage; the safety module is configured to disconnect the energy absorption unit to protect the absorption module when the absorption voltage of the absorption module is higher than a set voltage that the absorption module can bear.

In some embodiments, the absorption module comprises: a voltage dependent resistor; the piezoresistor and the protective tube are sequentially arranged between the anode of the direct current bus and the cathode of the branch bus.

In some embodiments, the energy absorbing unit comprises: a TVS tube; the TVS tube is configured to absorb the spike voltage.

In accordance with another aspect of the present invention, there is provided an electrical apparatus, including: the above-mentioned dc bus protection device.

In another aspect, the present invention provides a method for protecting a dc bus of an electrical apparatus, including: through an energy release unit, releasing the spike pulse voltage on the direct current bus under the condition that the spike pulse voltage on the direct current bus is greater than or equal to a first set voltage and less than a second set voltage; and the energy absorption unit is used for absorbing the spike pulse voltage on the direct current bus under the condition that the spike pulse voltage on the direct current bus is greater than or equal to a second set voltage.

In some embodiments, further comprising: detecting a spike voltage on the DC bus; determining a relationship between the detected spike voltage and a first set voltage and a second set voltage; if the detected spike pulse voltage is greater than or equal to a first set voltage and less than a second set voltage, controlling the energy release unit to be started; and if the detected spike pulse voltage is greater than or equal to a second set voltage, controlling the energy absorption unit to be started.

In some embodiments, the energy release unit comprises: a one-way module, a consumption module and a buffer module; the over-energy release unit releases spike pulse voltage on the direct current bus, and the over-energy release unit comprises: controlling, by the unidirectional module, a release direction of the spike voltage; consuming, by the consuming module, the spike voltage in a release direction of the spike voltage; storing and buffering, by the buffering module, the spike voltage in a release direction of the spike voltage.

In some embodiments, the energy absorbing unit comprises: an absorption module and a safety module; wherein, absorb the spike pulse voltage on the direct current bus through energy absorption unit, include: absorbing the spike pulse voltage through the absorption module; and through the safety module, under the condition that the absorption voltage of the absorption module is higher than the set voltage which can be borne by the absorption module, the energy absorption unit is disconnected to protect the absorption module.

Therefore, according to the scheme of the invention, under the condition that instantaneous impact or instantaneous high voltage occurs in the motor driving circuit, the instantaneous impact or instantaneous high voltage is released and/or absorbed, so that the components are protected from being damaged, the problem that the components are damaged by the instantaneous impact or instantaneous high voltage when the electrolytic capacitor is replaced by the thin-film capacitor in the motor driving circuit is solved, and the effect of avoiding the components from being damaged by the instantaneous impact or instantaneous high voltage is achieved.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.

Drawings

Fig. 1 is a schematic structural diagram of an embodiment of a dc bus protection device according to the present invention;

FIG. 2 is a schematic diagram of a motor driving circuit;

FIG. 3 is a schematic diagram of an inverter driving circuit using a thin film capacitor;

fig. 4 is a schematic flowchart of a dc bus protection method according to an embodiment of the present invention;

fig. 5 is a flowchart illustrating an embodiment of controlling the triggering timing of the energy release unit and the energy absorption unit in the method of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the specific embodiments of the present invention and the accompanying drawings. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

According to an embodiment of the present invention, there is provided a dc bus bar protecting device. Referring to fig. 1, a schematic diagram of an embodiment of the apparatus of the present invention is shown. The dc bus bar protecting apparatus may include: a bus protection unit; the bus protection unit is arranged on a direct current bus between a film capacitor and a bus capacitor in a power supply of the electrical equipment, namely, between a positive electrode and a negative electrode of the direct current bus of the power supply of the electrical equipment, and is positioned between the film capacitor and the bus capacitor in the power supply of the electrical equipment. A thin film capacitor, such as a fourth capacitor C4, is provided at the output of the rectifier bridge in the power supply. A bus capacitor, such as a sixth capacitor C6, is provided at the input of the inverter in the power supply. The bus bar protection unit may include: an energy releasing unit and/or an energy absorbing unit.

Specifically, in a case that the dc bus protection device can include an energy release unit, the energy release unit, such as the second circuit, can be configured to release the spike pulse voltage on the dc bus when the spike pulse voltage on the dc bus is greater than or equal to a first set voltage and less than a second set voltage, so as to avoid the spike pulse voltage from damaging the power supply of the electrical equipment and the components of the electrical equipment itself, protect the power supply or the driver of the electrical equipment, and even protect the electrical equipment itself.

Specifically, in a case that the dc bus protection device can include an energy absorption unit, the energy absorption unit, such as a third circuit, can be configured to absorb a spike pulse voltage on the dc bus when the spike pulse voltage on the dc bus is greater than or equal to a second set voltage, so as to avoid damage of the spike pulse voltage to a power supply of the electrical equipment and components of the electrical equipment itself, protect the power supply or a driver of the electrical equipment, and even protect the electrical equipment itself. The second setting voltage is greater than the first setting voltage, and if the first setting voltage is 1000V, the second setting voltage is 1100V.

For example: when the film capacitor is applied to an inversion technology in a driving scheme, instantaneous high voltage can be quickly absorbed under the condition that a motor of a driving system of electrical equipment such as an air conditioner is abnormally stopped, so that a driving plate is protected from being damaged.

Therefore, in the motor control scheme with the film capacitor, the instantaneous peak voltage of the bus can be quickly inhibited under the condition that the power grid fluctuates sharply or the system motor is stopped abnormally, so that the system is protected from being damaged.

In some embodiments, it can further include: a sampling unit and a control unit. The control unit can be used for controlling the opening and closing of the energy release unit and the energy absorption unit, and can be a hardware control circuit and a software control program.

Specifically, the sampling unit can be configured to detect a spike voltage on the dc bus when an electrical device is turned on.

For example: the power supply forms regular 6 pulses after being rectified by the rectifier bridge. In standby, the fourth capacitor C4 (usually selected to be several tens of microfarads) exists, so that the voltage is relatively stable after being smoothed by the fourth capacitor C4 in standby. When the motor is started, because the fourth capacitor C4 has no energy storage function, the voltage fluctuation smoothed by the fourth capacitor C4 is very large, and at the moment, the second circuit and the third circuit do not work. When the power grid fluctuation is large or the motor is abnormally stopped, one or more Ux with narrow pulse width and high peak value (more than 1000V) can be formed.

In particular, the control unit can be configured to determine a relationship between the detected spike voltage and a first set voltage and a second set voltage.

Furthermore, the control unit may be specifically configured to control the energy release unit to be turned on to release the energy of the spike pulse voltage through the energy release unit if the detected spike pulse voltage is greater than or equal to a first setting voltage and less than a second setting voltage.

Or, the control unit may be further configured to control the energy absorption unit to be turned on if the detected spike voltage is greater than or equal to a second set voltage, so as to absorb the energy of the spike voltage through the energy absorption unit.

Therefore, under the condition that an energy release unit such as a second circuit and an energy absorption unit such as a third circuit are simultaneously arranged in the direct-current bus protection device, a bus RDC (remote data center) discharge circuit, namely the second circuit, is adopted to release energy, then when the voltage is higher than the maximum value which can be borne by the second circuit, the third circuit is controlled to act to absorb the instantaneous high voltage, hardware-level protection is provided when the instantaneous overvoltage occurs, the instantaneous high-voltage impact generated when the power grid fluctuates greatly is absorbed, the system is not stopped, and the reliability is high; the motor protection circuit provides rapid protection when the motor is abnormally stopped, and can realize protection without additional voltage and current detection circuits, thereby greatly reducing the cost.

In some embodiments, the energy release unit can include: a one-way module, a consumption module, and a buffer module. The unidirectional module, the consumption module and the buffer module are sequentially arranged between the anode of the direct current bus and the cathode of the direct current bus to form a bus RDC (remote data center) bleeder circuit. Specifically, the fluid inlet end of the unidirectional module is connected to the positive pole of the direct current bus; and the fluid outlet end of the unidirectional module is connected to the cathode of the direct current bus after passing through the consumption module and the buffer module.

Wherein the unidirectional module is configurable to control a release direction of the spike voltage.

The consumption module is configured to consume the spike pulse voltage in a release direction of the spike pulse voltage.

The buffer module is configured to store and buffer the spike voltage in a release direction of the spike voltage.

Therefore, by adopting the bus RDC bleeder circuit, the diode unidirectional conduction characteristic, the electrolytic capacitor for storing instantaneous energy and the resistor for releasing energy, the power supply of the electrical equipment and the components of the electrical equipment are prevented from being damaged by spike pulse voltage, and the safety of the power supply of the electrical equipment and the safety of the electrical equipment are improved.

In some embodiments, the unidirectional module can include: a diode module (e.g., diode D). The consumable module can include: a dissipation resistor (e.g., a third resistor R3). The buffer module can include: a buffer capacitor (e.g., a fifth capacitor C5).

Wherein the anode of the diode module is connected to the positive pole of the DC bus. And the cathode of the diode module is connected to the cathode of the direct current bus after passing through the consumption resistor and the buffer capacitor.

For example: the diode D, the third resistor R3 and the fifth capacitor C5 form an RDC energy release loop; instantaneous spike high voltage can be released through the RDC energy release circuit. The fifth capacitor C5 is a buffer capacitor.

For example: when the power grid fluctuation is large or the motor is abnormally stopped, one or more Ux with narrow pulse width and high peak value (more than 1000V) can be formed, and when the voltage is lower than 1100V, the Ux is absorbed through a second circuit, wherein a diode D is responsible for conducting and leading in energy in a unidirectional mode, a third resistor R3 is responsible for consuming energy, and a fifth capacitor C5 is responsible for storing and buffering a small part of energy.

In some embodiments, the energy absorbing unit can include: an absorption module and a safety module. The absorption module and the safety module are sequentially connected between the anode of the direct current bus and the cathode of the direct current bus.

Wherein the absorption module is configurable to absorb the spike voltage.

The safety module can be configured to disconnect the energy absorption unit to protect the absorption module when an absorption voltage of the absorption module is higher than a set voltage that the absorption module can withstand.

For example: the third circuit is a voltage dependent resistor RV and a FUSE FUSE, and when the voltage is higher than the maximum value which can be borne by the second circuit, the third circuit acts to absorb the instantaneous high voltage. The piezoresistor RV can be 1100V (112 KM).

In some embodiments, the absorption module can include: a varistor (e.g., varistor RV). The piezoresistor and the protective tube are sequentially arranged between the anode of the direct current bus and the cathode of the branch bus.

For example: when the power grid fluctuation is large or the motor is abnormally stopped, one or more Ux with narrow pulse width and high peak value (more than 1000V) can be formed, and when the voltage is higher than 1100V, the Ux is absorbed by a third circuit. The voltage dependent resistor RV absorbs instantaneous high voltage, and the FUSE prevents the voltage dependent resistor RV from being damaged due to excessive absorbed energy.

In some embodiments, the energy absorbing unit can include: and a TVS tube. The TVS tube is configured to absorb the spike voltage. For example: the third circuit can be replaced by a voltage sensitive/absorbing device such as a TVS tube.

Through a large number of tests, the technical scheme of the invention provides hardware-level protection when instantaneous overvoltage occurs under the condition that instantaneous impact or instantaneous high voltage occurs in a motor driving circuit, so that the instantaneous high-voltage impact generated when the power grid has large fluctuation is absorbed, the system is not stopped, and the reliability is high.

According to the embodiment of the invention, the electrical equipment corresponding to the direct current bus protection device is also provided. The electric appliance can include: the above-mentioned dc bus protection device.

When the film capacitor is applied to an inversion technology in a driving scheme, after an electrolytic capacitor with a larger capacitance value is changed into a film capacitor with a smaller capacitance value, the voltage can fluctuate greatly, and if the power grid fluctuates greatly, the module can be damaged due to instantaneous impact generated; secondly, when the motor is abnormally stopped, due to the influence of the free wheel diode module, short-time sharp oscillation of voltage or current can be caused on the bus, namely, instantaneous high voltage is formed, and the module can be damaged. For example: and all devices connected with the bus PN are damaged, and the devices comprise a compressor IGBT, a fan IGBT, a switching power supply chip, a DSP chip direct current bus protection pin and the like.

In some embodiments, the present invention provides a protection circuit, in particular to a protection circuit of an air conditioning system, which can quickly absorb an instantaneous high voltage when a motor of an air conditioning driving system is abnormally stopped, so as to protect a driving board from being damaged.

Specifically, according to the scheme of the invention, when the film capacitor is applied to an inverter technology in a driving scheme, the direct-current bus protection circuit capable of absorbing instantaneous peak voltage can quickly absorb instantaneous high voltage under the condition that a motor of an air conditioner driving system is abnormally stopped, so that the driving plate is protected from being damaged.

In some embodiments, specific implementation processes of the scheme of the present invention can be exemplarily described with reference to the examples shown in fig. 2 and fig. 3.

According to the scheme, a bus RDC bleeder circuit (namely an RDC energy release loop) is adopted, instantaneous energy is stored by adopting an electrolytic capacitor through the unidirectional conduction characteristic of a diode, and the energy is released through a resistor; and then when the voltage is higher than the maximum value which can be borne by the second circuit, the third circuit is controlled to act to absorb the instantaneous high voltage. Therefore, the problems that the bus energy storage capacitor can only absorb part of high voltage, devices cannot be normally protected when the voltage is higher, and the capacitor C of the RDC energy release loop is damaged sometimes can be solved, hardware-level protection is provided when instantaneous overvoltage occurs, instantaneous high-voltage impact generated when the power grid fluctuates greatly is absorbed, the system is not stopped, and the reliability is high; the motor protection circuit provides rapid protection when the motor is abnormally stopped, and can realize protection without additional voltage and current detection circuits, thereby greatly reducing the cost.

Fig. 2 is a schematic structural diagram of a motor driving circuit. The motor drive circuit shown in fig. 2 can include: rectifier bridge, first circuit, third electric capacity C3 and inverter U1. The first circuit is located between the rectifier bridge and the third capacitor C3, and is connected to the dc bus. The third capacitor C3 is connected in parallel with the inverter U1, and the output of the inverter is connected to a motor such as a compressor. The first circuit can include a first capacitor C1, a second capacitor C2, a first resistor R1, and a second resistor R2. The series branch of the first capacitor C1 and the second capacitor C2 and the series branch of the first resistor R1 and the second resistor R2 are connected between the positive pole and the negative pole of the direct current bus in parallel, and the common end of the first capacitor C1 and the second capacitor C2 is connected with the common end of the first resistor R1 and the second resistor R2.

In the example shown in fig. 2, the first capacitor C1 and the second capacitor C2 are large-capacity electrolytic capacitors, the first resistor R1 and the second resistor R2 are voltage-sharing resistors, and the third capacitor C3 is a metallized polyester film Capacitor (CBB).

In the example shown in fig. 2, the power source forms a regular 6-pulse wave through the rectifier bridge, and forms a stable voltage through the equivalent first circuit (the equivalent capacitance value is usually thousands of microfarads), so as to be used by the module driving the motor. Along with the increase of the power of the motor, the capacity of the required first circuit also needs to be increased synchronously, so that the normal work of the motor can be ensured.

In some examples, the present invention provides a bus instantaneous peak voltage suppression circuit in a motor control scheme with a thin film capacitor, which can rapidly suppress instantaneous peak voltage in the case of sudden power grid fluctuation or abnormal shutdown of a system motor, thereby protecting the system from damage.

Fig. 3 is a schematic structural diagram of an inverter driving circuit using a thin film capacitor. As shown in fig. 3, the inverter driving circuit using the thin film capacitor may include: the rectifier bridge, the fourth capacitor C4, the third circuit, the second circuit, the sixth capacitor C6 and the inverter U1. The rectifier bridge, the fourth capacitor C4, the third circuit, the second circuit, the sixth capacitor C6 and the inverter U1 are sequentially arranged between the alternating current power supply and the motor such as a compressor.

A third circuit, which can include: the absorption module and the insurance module are arranged in series. When the voltage is higher than the maximum value which can be borne by the second circuit, the third circuit acts to absorb the instantaneous high voltage.

Wherein, insurance module includes: a FUSE. An absorption module comprising: the piezoresistor RV can be 1100V (112 KM).

In use, the third circuit may be replaced by a voltage sensitive/absorbing device such as a TVS transistor.

The second circuit (i.e., energy release unit) can include: the RDC energy release loop is composed of a unidirectional conduction tube (namely, a unidirectional module), an energy consumption resistor (namely, a consumption module) and a small energy storage capacitor (namely, a buffer module). Through this RDC energy release circuit, can release the instantaneous spike high pressure.

Wherein, one-way conduction pipe includes: and a diode D. An energy dissipating resistor comprising: and a third resistor R3. A small energy storage capacitor comprising: a fifth capacitor C5. The fifth capacitor C5 is a buffer capacitor. In the diode D, the third resistor R3 and the fifth capacitor C5, the anode of the diode D is connected to one end of the bus voltage, and the cathode of the diode D is connected to the other end of the bus voltage through the third resistor R3 and the fifth capacitor C5.

In use, the second circuit can add some over-voltage hardware decision circuitry to trigger the RDC energy release loop action.

In the example shown in fig. 3, the fourth capacitor C4 is a film capacitor, and the capacitance is usually several tens of microfarads. The sixth capacitor C6 is a metallized polyester film Capacitor (CBB) and is used for filtering high-frequency interference signals in the switching process of the IGBT.

As shown in fig. 3, the power is rectified by the rectifier bridge to form 6 regular pulses. In standby, the fourth capacitor C4 (usually selected to be several tens of microfarads) exists, so that the voltage is relatively stable after being smoothed by the fourth capacitor C4 in standby. When the motor is started, because the fourth capacitor C4 has no energy storage function, the voltage fluctuation smoothed by the fourth capacitor C4 is very large, and at the moment, the second circuit and the third circuit do not work. When the power grid fluctuation is large or the motor is abnormally stopped, one or more Ux with narrow pulse width and high peak value (more than 1000V) can be formed, and when the voltage is lower than 1100V, the Ux is absorbed through a second circuit, wherein a diode D is responsible for conducting and leading in energy in a one-way mode, a third resistor R3 is responsible for consuming energy, and a fifth capacitor C5 is responsible for storing and buffering a small part of energy; when the voltage is higher than 1100V, it is absorbed by the third circuit. The voltage dependent resistor RV absorbs instantaneous high voltage, and the FUSE prevents the voltage dependent resistor RV from being damaged due to excessive absorbed energy.

Since the processes and functions implemented by the electrical apparatus of this embodiment substantially correspond to the embodiments, principles, and examples of the apparatus shown in fig. 1, the descriptions of the embodiment are not detailed herein, and refer to the related descriptions in the embodiments, which are not described herein again.

Through a large number of tests, the technical scheme of the invention provides rapid protection when the motor is abnormally stopped under the condition of instantaneous impact or instantaneous high voltage in the motor driving circuit, and can realize protection without additional voltage and current detection circuits, thereby greatly reducing the cost.

According to an embodiment of the present invention, a method for protecting a dc bus of an electrical device corresponding to the electrical device is also provided, as shown in fig. 4, which is a schematic flow chart of an embodiment of the method of the present invention. The direct-current bus protection method for the electrical equipment can comprise the following steps: step S110 and/or step S120.

At step S110, in a case that the method for protecting the dc bus of the electrical equipment can include an energy release unit, the energy release unit, such as a second circuit, releases the spike pulse voltage on the dc bus when the spike pulse voltage on the dc bus is greater than or equal to a first set voltage and less than a second set voltage, so as to prevent the spike pulse voltage from damaging the power supply of the electrical equipment and the components of the electrical equipment, protect the power supply or the driver of the electrical equipment, and even protect the electrical equipment itself.

At step S120, in a case that the method for protecting the dc bus of the electrical equipment can include an energy absorption unit, the energy absorption unit, such as a third circuit, absorbs the spike pulse voltage on the dc bus when the spike pulse voltage on the dc bus is greater than or equal to a second set voltage, so as to prevent the spike pulse voltage from damaging the power supply of the electrical equipment and the components of the electrical equipment, protect the power supply or the driver of the electrical equipment, and even protect the electrical equipment itself. The second setting voltage is greater than the first setting voltage, and if the first setting voltage is 1000V, the second setting voltage is 1100V.

In some embodiments, it can further include: the process of controlling the triggering timing of the energy release unit and the energy absorption unit can be specifically referred to the following exemplary description.

In the following, referring to a schematic flow chart of an embodiment of the method of the present invention shown in fig. 5, which is used to control the triggering timings of the energy release unit and the energy absorption unit, a specific process for controlling the triggering timings of the energy release unit and the energy absorption unit is further described, which can include: step S210 to step S240.

Step S210, detecting the spike pulse voltage on the direct current bus by a sampling unit under the condition that the electrical equipment is started.

In step S220, the relationship between the detected spike voltage and the first and second set voltages is determined by the control unit.

In step S230, if the detected spike voltage is greater than or equal to a first setting voltage and less than a second setting voltage, the energy release unit is controlled to be turned on to release the energy of the spike voltage through the energy release unit.

In step S240, if the detected spike voltage is greater than or equal to a second set voltage, the energy absorption unit is controlled to be turned on, so as to absorb the energy of the spike voltage through the energy absorption unit.

Therefore, under the condition that an energy release unit such as a second circuit and an energy absorption unit such as a third circuit are simultaneously arranged in the direct current bus protection method of the electrical equipment, a bus RDC (remote data center) bleeder circuit, namely the second circuit, is adopted to release energy, then when the voltage is higher than the maximum value which can be borne by the second circuit, the third circuit is controlled to act to absorb the instantaneous high voltage, hardware-level protection is provided when the instantaneous overvoltage occurs, the instantaneous high-voltage impact generated when the power grid has large fluctuation is absorbed, the system is not stopped, and the reliability is high; the motor protection circuit provides rapid protection when the motor is abnormally stopped, and can realize protection without additional voltage and current detection circuits, thereby greatly reducing the cost.

In some embodiments, the energy release unit can include: a one-way module, a consumption module and a buffer module; the unidirectional module, the consumption module and the buffer module are sequentially arranged between the anode of the direct current bus and the cathode of the direct current bus to form a bus RDC (remote data center) bleeder circuit. Specifically, the fluid inlet end of the unidirectional module is connected to the positive pole of the direct current bus; and the fluid outlet end of the unidirectional module is connected to the cathode of the direct current bus after passing through the consumption module and the buffer module.

The over-energy releasing unit releases the spike pulse voltage on the dc bus, and may include: controlling, by the unidirectional module, a release direction of the spike voltage; consuming, by the consuming module, the spike voltage in a release direction of the spike voltage; storing and buffering, by the buffering module, the spike voltage in a release direction of the spike voltage.

Wherein, absorbing the spike pulse voltage on the dc bus by the energy absorption unit can include: absorbing the spike pulse voltage through the absorption module; and through the safety module, under the condition that the absorption voltage of the absorption module is higher than the set voltage which can be borne by the absorption module, the energy absorption unit is disconnected to protect the absorption module.

For example: the third circuit is a voltage dependent resistor RV and a FUSE FUSE, and when the voltage is higher than the maximum value which can be borne by the second circuit, the third circuit acts to absorb the instantaneous high voltage.

Since the processes and functions implemented by the method of the present embodiment substantially correspond to the embodiments, principles, and examples of the electrical apparatus, reference may be made to the related descriptions in the foregoing embodiments without being detailed in the description of the present embodiment.

Through a large amount of tests verification, adopt the technical scheme of this embodiment, through when being applied to the contravariant technique among the drive scheme with film capacitor, through can absorbing instantaneous peak voltage, can be when electrical equipment like the motor of air conditioner drive system the condition of unusual shut down appears, can absorb instantaneous high pressure fast to the protection drive plate is not damaged.

In summary, it is readily understood by those skilled in the art that the advantageous modes described above can be freely combined and superimposed without conflict.

The above description is only an example of the present invention, and is not intended to limit the present invention, and it is obvious to those skilled in the art that various modifications and variations can be made in the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A DC bus protection device, comprising: a bus protection unit; the bus protection unit is arranged on a direct current bus between a film capacitor and a bus capacitor in a power supply of the electrical equipment; the bus bar protection unit includes: an energy releasing unit and/or an energy absorbing unit; wherein the content of the first and second substances,

the energy release unit is configured to release the spike pulse voltage on the direct current bus under the condition that the spike pulse voltage on the direct current bus is greater than or equal to a first set voltage and smaller than a second set voltage;

the energy absorption unit is configured to absorb the spike pulse voltage on the direct current bus when the spike pulse voltage on the direct current bus is greater than or equal to a second set voltage.

2. The dc bus bar protection device according to claim 1, further comprising: a sampling unit and a control unit; wherein the content of the first and second substances,

the sampling unit is configured to detect spike pulse voltage on the direct current bus;

the control unit configured to determine a relationship between the detected spike voltage and a first set voltage and a second set voltage;

if the detected spike pulse voltage is greater than or equal to a first set voltage and less than a second set voltage, controlling the energy release unit to be started;

and if the detected spike pulse voltage is greater than or equal to a second set voltage, controlling the energy absorption unit to be started.

3. The dc bus bar protection device according to claim 1 or 2, wherein the energy releasing unit comprises: a one-way module, a consumption module and a buffer module; wherein the content of the first and second substances,

the unidirectional module is configured to control a release direction of the spike voltage;

the consumption module is configured to consume the spike pulse voltage in a release direction of the spike pulse voltage;

4. The dc bus bar protection device of claim 3, wherein the unidirectional module comprises: a diode module; the consumable module, comprising: a consumption resistance; the buffer module comprises: a buffer capacitor; wherein the content of the first and second substances,

the anode of the diode module is connected to the anode of the direct current bus; and the cathode of the diode module is connected to the cathode of the direct current bus after passing through the consumption resistor and the buffer capacitor.

5. The dc bus bar protection device according to claim 1 or 2, wherein the energy absorption unit comprises: an absorption module and a safety module; wherein the content of the first and second substances,

the absorption module is configured to absorb the spike pulse voltage;

the safety module is configured to disconnect the energy absorption unit to protect the absorption module when the absorption voltage of the absorption module is higher than a set voltage that the absorption module can bear.

6. The dc bus bar protection device of claim 5, wherein the absorption module comprises: a voltage dependent resistor; the piezoresistor and the protective tube are sequentially arranged between the anode of the direct current bus and the cathode of the branch bus.

7. The dc bus bar protection device according to claim 1 or 2, wherein the energy absorption unit comprises: a TVS tube; the TVS tube is configured to absorb the spike voltage.

8. An electrical device, comprising: the dc bus bar protection device of any one of claims 1 to 7.

9. A direct current bus protection method of electrical equipment is characterized by comprising the following steps:

through an energy release unit, releasing the spike pulse voltage on the direct current bus under the condition that the spike pulse voltage on the direct current bus is greater than or equal to a first set voltage and less than a second set voltage;

and the energy absorption unit is used for absorbing the spike pulse voltage on the direct current bus under the condition that the spike pulse voltage on the direct current bus is greater than or equal to a second set voltage.

10. The method for protecting a direct current bus of an electrical apparatus according to claim 9, further comprising:

detecting a spike voltage on the DC bus;

determining a relationship between the detected spike voltage and a first set voltage and a second set voltage;

11. The method for protecting a direct current bus of an electric device according to claim 9 or 10, wherein the energy releasing unit comprises: a one-way module, a consumption module and a buffer module;

the over-energy release unit releases spike pulse voltage on the direct current bus, and the over-energy release unit comprises:

controlling, by the unidirectional module, a release direction of the spike voltage;

consuming, by the consuming module, the spike voltage in a release direction of the spike voltage;

storing and buffering, by the buffering module, the spike voltage in a release direction of the spike voltage.

12. The method for protecting a direct current bus of an electric device according to claim 9 or 10, wherein the energy absorption unit comprises: an absorption module and a safety module;

wherein, absorb the spike pulse voltage on the direct current bus through energy absorption unit, include:

absorbing the spike pulse voltage through the absorption module;

and through the safety module, under the condition that the absorption voltage of the absorption module is higher than the set voltage which can be borne by the absorption module, the energy absorption unit is disconnected to protect the absorption module.