A driving method, a driving circuit and a driving system for a compressor driving circuit

Abstract

This disclosure relates to a driving method, driving circuit, and driving system for a compressor drive circuit. The driving method includes: controlling a buck-boost circuit to adjust the DC input voltage of the compressor drive circuit to a DC intermediate voltage; controlling an inverter circuit to adjust the DC intermediate voltage to an AC output voltage of the compressor drive circuit; wherein the inverter circuit's inverter modulation degree is a fixed value equal to or slightly less than 1; controlling the duty cycle of a set switch in the buck-boost switching transistor combination according to the buck state, and controlling the duty cycle of a set switch in the boost-boost switching transistor combination according to the boost state to adjust the AC output voltage. Through the technical solution of this disclosure, the upper limit of the AC output voltage is not affected by the magnitude of the DC input voltage provided by the mobile device's power platform, expanding the selection range of linear compressor models, and ensuring a good AC sine wave waveform and low harmonic distortion rate even when outputting a low amplitude AC voltage.

Description

Technical Field

[0001] The present disclosure relates to the technical field of compressor driving, and in particular to a driving method, a driving circuit and a driving system of a compressor driving circuit. Background Art

[0002] The CCD imaging devices in space-cooled infrared detection equipment and the germanium crystals in high-purity germanium detection equipment need to work in a low-temperature environment. The mobile pulse tube refrigeration system is used in space-cooled infrared detection equipment and high-purity germanium detection equipment because of its advantages such as no mechanical vibration source at the cold end and long service life of the mechanical structure, providing a cold source for CCD imaging devices and germanium crystals. Space-cooled infrared detection equipment and high-purity germanium detection equipment usually use DC power supplies such as solar cells and lithium batteries, while the linear compressors used as compression units of the pulse tube refrigeration system in these devices require AC power to drive. Therefore, a corresponding circuit is required to convert the DC power supply into the AC power supply required by the linear compressor. The linear compressor drive circuit is designed to achieve this function.

[0003] In the prior art, the AC output voltage of the linear compressor driving circuit is limited by the DC voltage input size provided by the mobile device power platform, which reduces the range of selectable linear compressor models and may even require the re-development of the linear compressor. In addition, when the existing linear compressor driving circuit outputs a low-amplitude AC voltage, a low inverter modulation index needs to be set, and an excessively low inverter modulation index will cause a significant increase in the harmonic distortion rate. Summary of the invention

[0004] In order to solve the above technical problems or at least partially solve the above technical problems, the present disclosure provides a driving method, a driving circuit and a driving system for a compressor driving circuit. The upper limit of the AC output voltage is not affected by the DC voltage input size provided by the power platform of the mobile device, which expands the selection range of linear compressor models. When outputting a low-amplitude AC voltage, it can still ensure that the output AC sinusoidal wave has a good waveform and a low harmonic distortion rate.

[0005] In a first aspect, the present disclosure provides a driving method of a compressor driving circuit, wherein the compressor driving circuit comprises a buck-boost circuit and an inverter circuit, wherein the buck-boost circuit comprises a boost switch tube combination and a buck switch tube combination; wherein the switch states of the two switch tubes in the boost switch tube combination are complementary, and the switch states of the two switch tubes in the buck switch tube combination are complementary;

[0006] The driving method of the compressor driving circuit comprises:

[0007] Controlling the buck-boost circuit to adjust the DC input voltage of the compressor drive circuit to a DC intermediate voltage;

[0008] Controlling the inverter circuit to adjust the DC intermediate voltage to the AC output voltage of the compressor drive circuit; wherein the inverter modulation degree of the inverter circuit is a fixed value;

[0009] Wherein, when the buck-boost circuit is in a buck state, the switch tube electrically connected to the negative end of the DC power in the boost switch tube combination is controlled to be turned off, the switch tube on the DC positive end transmission line in the boost switch tube combination is controlled to be turned on, and the duty cycle of the switch tube in the buck switch tube combination is controlled to be set to adjust the AC output voltage;

[0010] When the buck-boost circuit is in a boost state, the switch tube electrically connected to the negative end of the DC power in the buck switch tube combination is controlled to be turned off, the switch tube on the DC positive end transmission line in the buck switch tube combination is controlled to be turned on, and the duty cycle of the switch tube in the boost switch tube combination is controlled to be set to adjust the AC output voltage.

[0011] Optionally, the buck-boost circuit further includes a first inductor and a first capacitor, the buck switch tube combination includes a first switch tube and a second switch tube, and the boost switch tube combination includes a third switch tube and a fourth switch tube, the first switch tube, the first inductor and the fourth switch tube are sequentially connected in series between the positive end of the DC input voltage and the positive end of the DC intermediate voltage, the second switch tube is connected in series between the first end of the first inductor and the negative end of the DC input voltage, the third switch tube is connected in series between the second end of the first inductor and the negative end of the DC input voltage, the first capacitor is connected in series between the positive end of the DC intermediate voltage and the negative end of the DC intermediate voltage, and the negative end of the DC input voltage is electrically connected to the negative end of the DC intermediate voltage;

[0012] When the buck-boost circuit is in a buck state, the driving method of the compressor driving circuit includes:

[0013] The third switch tube is controlled to be normally closed and the fourth switch tube is controlled to be normally open, and the first switch tube and the second switch tube are controlled to be alternately turned on; wherein the set switch tube in the step-down switch tube combination is the first switch tube or the second switch tube.

[0014] Optionally, when the buck-boost circuit is in a boost state, the driving method of the compressor driving circuit includes:

[0015] The second switch tube is controlled to be normally closed and the first switch tube is controlled to be normally open, and the third switch tube and the fourth switch tube are controlled to be alternately turned on; wherein the set switch tube in the boost switch tube combination is the third switch tube or the fourth switch tube.

[0016] In a second aspect, an embodiment of the present disclosure further provides a compressor driving circuit, which is driven by the driving method of the compressor driving circuit described in the first aspect, and the buck-boost circuit is electrically connected to the inverter circuit.

[0017] Optionally, the inverter circuit includes:

[0018] An inverter bridge circuit and an integration circuit, wherein the inverter bridge circuit is electrically connected to the integration circuit, the inverter bridge circuit is used to convert the DC intermediate voltage into an AC intermediate voltage, and the integration circuit is used to adjust the AC intermediate voltage to the AC output voltage; wherein the AC output voltage is a sinusoidal wave voltage.

[0019] Optionally, the switch tube in the buck-boost circuit and / or the inverter circuit adopts a surface-mount packaged power MOSFET of model IRHNA67160.

[0020] In a third aspect, an embodiment of the present disclosure provides a compressor drive system, comprising a control circuit and a compressor drive circuit as described in the second aspect, wherein the control circuit is electrically connected to the compressor drive circuit, and the control circuit is used to control the compressor drive circuit to generate the AC output voltage.

[0021] Optionally, the control circuit includes:

[0022] A processor, a memory, a first gate drive chip and a second gate drive chip, wherein the processor is electrically connected to a host computer, the memory, the first gate drive chip and the second gate drive chip respectively, the first gate drive chip is electrically connected to the buck-boost circuit, and the second gate drive chip is electrically connected to the inverter circuit;

[0023] The processor is used to drive the buck-boost circuit through the first gate drive chip according to the duty cycle information sent by the host computer, and is used to read the set sinusoidal pulse width table stored in the memory to output a sinusoidal pulse width modulation signal to the second gate drive chip, and drive the inverter circuit through the second gate drive chip.

[0024] Optionally, the processor uses an anti-fuse FPGA of model A54SX72A-CQ208B, and the memory uses a PROM memory of model HS1-6664RH-Q.

[0025] Optionally, the first gate driving chip and / or the second gate driving chip adopts a high-speed MOSFET driving chip of model IR2110L4SCS.

[0026] Compared with the prior art, the technical solution provided by the embodiments of the present disclosure has the following advantages:

[0027] The embodiment of the present disclosure provides a driving method of a compressor driving circuit, wherein the compressor driving circuit includes a buck-boost circuit and an inverter circuit, wherein the buck-boost circuit includes a boost switch tube combination and a buck switch tube combination, wherein the switch states of the two switch tubes in the boost switch tube combination are complementary, and the switch states of the two switch tubes in the buck switch tube combination are complementary; the driving method of the compressor driving circuit includes: controlling the buck-boost circuit to adjust the DC input voltage of the compressor driving circuit to a DC intermediate voltage; controlling the inverter circuit to adjust the DC intermediate voltage to an AC output voltage of the compressor driving circuit; wherein the inverter modulation circuit The degree is a fixed value equal to or slightly less than 1; when the buck-boost circuit is in the buck state, the switch tube electrically connected to the negative end of the DC power in the boost switch tube combination is controlled to be turned off, the switch tube on the DC positive end transmission line in the boost switch tube combination is controlled to be turned on, and the duty cycle of the set switch tube in the buck switch tube combination is controlled to adjust the AC output voltage; when the buck-boost circuit is in the boost state, the switch tube electrically connected to the negative end of the DC power in the buck switch tube combination is controlled to be turned off, the switch tube on the DC positive end transmission line in the buck switch tube combination is controlled to be turned on, and the duty cycle of the set switch tube in the boost switch tube combination is controlled to adjust the AC output voltage. Therefore, the disclosed embodiment improves the compressor driving circuit so that it has the buck-boost function, thereby ensuring that the upper limit of the AC output voltage is not affected by the DC voltage input size provided by the mobile device power platform, expanding the selection range of linear compressor models. At the same time, the improved circuit can set the inverter modulation index to a fixed value equal to or slightly less than 1. It is only necessary to adjust the duty cycle of the switch tubes in the boost switch tube combination and the buck switch tube combination to adjust the amplitude of the AC output voltage. When outputting a low-amplitude AC voltage, it can still be ensured that the output AC sinusoidal wave has a good waveform and a low harmonic distortion rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0030] Figure 1 A flowchart of a driving method of a compressor driving circuit is provided for an embodiment of the present disclosure;

[0031] Figure 2 A schematic diagram of the structure of a compressor driving circuit provided by an embodiment of the present disclosure;

[0032] Figure 3 A schematic diagram of a sinusoidal pulse width modulation waveform provided in an embodiment of the present disclosure;

[0033] Figure 4 A schematic diagram of timing control of a switch tube in a buck-boost circuit in a buck state provided by an embodiment of the present disclosure;

[0034] Figure 5 A schematic diagram of timing control of a switch tube in a buck-boost circuit in a boost state provided by an embodiment of the present disclosure;

[0035] Figure 6 A schematic structural diagram of a compressor drive system provided in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0036] In order to more clearly understand the above-mentioned objectives, features and advantages of the present disclosure, the scheme of the present disclosure will be further described below. It should be noted that the embodiments of the present disclosure and the features in the embodiments can be combined with each other without conflict.

[0037] In the following description, many specific details are set forth to facilitate a full understanding of the present disclosure, but the present disclosure may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present disclosure, rather than all of the embodiments.

[0038] Figure 1 A flowchart of a method for driving a compressor drive circuit is provided for an embodiment of the present disclosure. The method for driving a compressor drive circuit can be applied in a scenario where a compressor drive circuit needs to be driven, and can be executed by a compressor drive system provided by an embodiment of the present disclosure, and the compressor drive system can be implemented in software and / or hardware. Figure 1 As shown, the driving method of the compressor driving circuit includes:

[0039] S201: Control the buck-boost circuit to adjust the DC input voltage of the compressor drive circuit to a DC intermediate voltage.

[0040] Figure 2 Schematic diagram of a compressor drive circuit provided by an embodiment of the present disclosure. Figure 2 As shown, the compressor driving circuit includes a buck-boost circuit 11 and an inverter circuit 12, the buck-boost circuit 11 is electrically connected to the inverter circuit 12, and the buck-boost circuit 11 includes a boost switch tube combination 112 and a buck switch tube combination 111. The switch states of the two switch tubes in the boost switch tube combination 112 are complementary, and the switch states of the two switch tubes in the buck switch tube combination 111 are complementary.

[0041] Specifically, when a mobile device power platform such as a solar cell or a lithium battery provides a DC input voltage to the compressor drive circuit, the buck-boost circuit 11 adjusts the DC input voltage to a DC intermediate voltage.

[0042] S202: Control the inverter circuit to adjust the DC intermediate voltage to the AC output voltage of the compressor drive circuit; wherein the inverter modulation index of the inverter circuit is a fixed value equal to or slightly less than 1.

[0043] Figure 3 A schematic diagram of a sinusoidal pulse width modulation waveform provided in an embodiment of the present disclosure. Figure 3 In the rectangular coordinate system above, the horizontal axis represents time t, and the vertical axis represents the sinusoidal AC output voltage U of the compressor drive circuit. out , Figure 3 In the rectangular coordinate system below, the horizontal axis represents time t, and the vertical axis represents the voltage difference between point A and point B in the compressor drive circuit, that is, the AC intermediate voltage U m , AC intermediate voltage U m After integration of the inductor and capacitor, the sinusoidal AC output voltage U is obtained. out , that is, an AC voltage whose magnitude and direction change with time according to the law of a sine function is obtained. In the embodiments disclosed herein, unless otherwise specified, the AC output voltage U out The values ​​are all effective values.

[0044] like Figure 3 As shown, the sinusoidal AC intermediate voltage U m The time width of each segmented square pulse in the first half of the cycle can be expressed as:

[0045]

[0046] δ i represents the time width of the pulse of the i-th segment, λ is the inverter modulation degree, T is the sine wave period, and N is the number of segments in half a sine wave period.

[0047] Based on the symmetry of the sine wave, the time width of each segmented square pulse in the second half of the sine wave can be expressed as:

[0048]

[0049] Referring to the above formula, in the existing compressor drive circuit, the method of adjusting the inverter modulation index λ is used to adjust the AC output voltage U out, which requires calculating and updating the sinusoidal pulse width table corresponding to the inverter modulation index λ. According to the SPWM (Sinusoidal Pulse Width Modulation) modulation theory, the value range of the inverter modulation index λ is greater than or equal to 0 and less than or equal to 1. The value of the inverter modulation index λ is negatively correlated with the harmonic distortion rate, that is, the harmonic distortion rate increases as the inverter modulation index λ decreases. When the inverter modulation index λ is less than 0.2, the harmonic distortion rate will increase significantly, which also leads to the required AC output voltage U out When it is low, it can only be achieved by reducing the inverter modulation index λ, which leads to harmonic distortion problems.

[0050] The DC input voltage U of the compressor drive circuit in the prior art in With AC output voltage U out The relationship between them satisfies the following formula:

[0051]

[0052] Among them, λ is the inverter modulation index. From the above formula, we can know that the AC output voltage U out Limited by DC input voltage U in The size of the linear compressor reduces the range of available linear compressor models and may even require the re-development of the linear compressor.

[0053] In the embodiment of the present disclosure, when the buck-boost circuit 11 is in the buck state, the switch tube electrically connected to the negative end of the DC power in the boost switch tube combination 112 is controlled to be turned off, the switch tube on the DC positive end transmission line in the boost switch tube combination 112 is controlled to be turned on, and the duty cycle of the switch tube in the buck switch tube combination 111 is controlled to be set to adjust the AC output voltage U out When the buck-boost circuit 11 is in the boost state, the switch tube electrically connected to the negative end of the DC power in the buck switch tube combination 111 is turned off, the switch tube on the DC positive end transmission line in the buck switch tube combination 111 is turned on, and the duty cycle of the switch tube in the boost switch tube combination 112 is set to adjust the AC output voltage U out .

[0054] Specifically, the AC output voltage U can be changed by adjusting only the duty cycle of the switch set in the step-down switch tube combination 111 and the duty cycle of the switch set in the step-up switch tube combination 112. out In order to reduce the harmonic distortion rate, the value of the inverter modulation index λ should be increased as much as possible under permitted circumstances. In the embodiment of the present disclosure, the inverter modulation index λ of the inverter circuit 12 is set to a fixed value of 1 or a fixed value slightly less than 1, thereby avoiding the problem of deterioration of the harmonic distortion rate index caused by the method of reducing the inverter modulation index λ when outputting a low-amplitude AC voltage.

[0055] The disclosed embodiment improves the compressor driving circuit so that it has a step-up and step-down function, thereby ensuring that the upper limit of the AC output voltage is not affected by the DC voltage input size provided by the mobile device power platform, expanding the selection range of linear compressor models, and at the same time, the improved circuit inverter modulation index can be set to a fixed value equal to or slightly less than 1. It is only necessary to adjust the duty cycle of the switch tubes in the boost switch tube combination 112 and the buck switch tube combination 111 to adjust the amplitude of the AC output voltage. When outputting a low-amplitude AC voltage, it can still be ensured that the output AC sine wave has a good waveform and a low harmonic distortion rate.

[0056] Alternatively, if Figure 2 As shown, the buck-boost circuit 11 further includes a first inductor L1 and a first capacitor C1, the buck switch tube combination 111 includes a first switch tube S1 and a second switch tube S2, the boost switch tube combination 112 includes a third switch tube S3 and a fourth switch tube S4, and the first switch tube S1, the first inductor and the fourth switch tube S4 are connected in series to the DC input voltage U in The positive terminal and the DC intermediate voltage U dc The second switch tube S2 is connected in series with the first end of the first inductor L1 and the DC input voltage U in The third switch tube S3 is connected in series with the second end of the first inductor L1 and the DC input voltage U in The first capacitor C1 is connected in series to the DC intermediate voltage U dc The positive terminal and the DC intermediate voltage U dc Between the negative terminals, the DC input voltage U in The negative terminal and the DC intermediate voltage U dc The negative terminal of the

[0057] When the buck-boost circuit 11 is in the buck state, the driving method of the compressor drive circuit includes: controlling the third switch tube S3 to be normally closed and controlling the fourth switch tube S4 to be normally open, and controlling the first switch tube S1 and the second switch tube S2 to be alternately turned on; wherein, the set switch tube in the buck switch tube combination 111 is the first switch tube S1 or the second switch tube S2. It should be noted that, in the embodiment of the present disclosure, the drain of the switch tube is set as the first end, and the source of the switch tube is set as the second end. In the buck-boost circuit 11, in order to avoid a short circuit, the first switch tube S1 and the second switch tube S2 are complementary and are not turned on at the same time; the third switch tube S3 and the fourth switch tube S4 are complementary and are not turned on at the same time. The switch tube can use pulse width modulation technology to control its switching state.

[0058] Specifically, combined Figure 2 and Figure 3 , DC input voltage U in With DC intermediate voltage U dc The relationship satisfies the following formula:

[0059]

[0060] Wherein, M1 is the duty cycle of the first switch tube S1 in the buck switch tube combination 111 , and M2 is the duty cycle of the third switch tube S3 in the boost switch tube combination 112 .

[0061] DC intermediate voltage U dc With AC output voltage U out The relationship satisfies the following formula:

[0062]

[0063] Here, λ is the inverter modulation index of the inverter circuit 12 .

[0064] The DC input voltage U in With DC intermediate voltage U dc The relationship formula and DC intermediate voltage U dc With AC output voltage U out The DC input voltage U is obtained by combining the relationship formulas of in With AC output voltage U out The relationship satisfies the following formula:

[0065]

[0066] Specifically, when the DC input voltage U in Higher, but the linear compressor electrical impedance is small, the required voltage U out When the voltage is low, the buck-boost circuit 11 should be in a buck state. Figure 4 A schematic diagram of timing control of a switch tube in a buck-boost circuit in a buck state is provided in an embodiment of the present disclosure, which can be used as follows Figure 4 The square wave pulse signal shown is used to control the switch state change of the switch tube in the buck-boost circuit 11 in the buck state, wherein the high level signal H represents the control switch tube to be turned on, and the low level signal L represents the control switch tube to be turned off.

[0067] like Figure 4 As shown, in each pulse width modulation period T1, the fourth switch tube S4 is in a normally open state, the third switch tube S3 is in a normally closed state, and the first switch tube S1 and the second switch tube S2 are alternately turned on. in The converted DC voltage U dc To ensure the converted DC voltage U dc Less than DC input voltage U in , set the duty cycle M2 of the switch tube in the boost switch tube combination 112 to 0, set the inverter modulation index to a fixed value of 1 and substitute the DC input voltage U in With AC output voltage Uout The relationship formula is:

[0068]

[0069] Since the duty cycle M1 of the first switch tube S1 in the step-down switch tube assembly 111 is less than or equal to 1, the AC output voltage U out Less than DC input voltage U in The duty cycle M1 of the first switch tube S1 in the step-down switch tube combination 111, the first switch tube S1 in each pulse width modulation period T1, and the opening time t of the first switch tube S1 in the T1 period on1 The relationship satisfies the following formula:

[0070]

[0071] The set switch tube in the step-down switch tube combination 111 can be the first switch tube S1 or the second switch tube S2. M1 in the above formula is the duty cycle of the first switch tube S1. The sum of the duty cycles of the first switch tube S1 and the second switch tube S2 is equal to 1. The duty cycle of the second switch tube S2 can also be used to represent the DC input voltage U in With AC output voltage U out The embodiment of the present disclosure does not limit this.

[0072] In this way, while ensuring that the inverter modulation index λ is a fixed value of 1, by adjusting the step-down switch tube combination 111 to set the duty cycle of the switch tube, the compressor drive circuit can play a role in stepping down the voltage, thereby reducing the harmonic distortion rate, and when outputting a low-amplitude AC voltage, it can still be ensured that the output AC sine wave has a good waveform and a low harmonic distortion rate.

[0073] Optionally, when the buck-boost circuit 11 is in the boost state, the driving method of the compressor driving circuit includes: controlling the second switch tube S2 to be normally closed and controlling the first switch tube S1 to be normally open, and controlling the third switch tube S3 and the fourth switch tube S4 to be alternately turned on; wherein, the set switch tube in the boost switch tube combination 112 is the third switch tube S3 or the fourth switch tube S4.

[0074] Specifically, when the DC input voltage U in Low, but the linear compressor has a large electrical impedance, and the required voltage U out When it is higher, the buck-boost circuit 11 is in a boost state. Figure 5 A control timing diagram of a switch tube in a buck-boost circuit in a boost state is provided in an embodiment of the present disclosure, which can be used as follows Figure 5 The square wave pulse signal shown is used to control the switch state change of the switch tube in the buck-boost circuit 11 in the boost state, wherein the high level signal H represents the control switch tube to be turned on, and the low level signal H represents the control switch tube to be turned off.

[0075] like Figure 5 As shown, in each pulse width modulation period T1, the first switch tube S1 is in a normally open state, the second switch tube S2 is in a normally closed state, and the third switch tube S3 and the fourth switch tube S4 are alternately turned on. in The converted DC voltage U dc To ensure the converted DC voltage U dc Greater than DC input voltage U in , set the duty cycle M1 of the switch tube in the boost switch tube combination 112 to 1, set the inverter modulation index λ to a fixed value of 1 and substitute the DC input voltage U in With AC output voltage U out The relationship formula is:

[0076]

[0077] Since the duty cycle M2 of the third switch tube S3 in the boost switch tube assembly 112 is less than or equal to 1, the AC output voltage U out Greater than DC input voltage U in The duty cycle M2 of the third switch tube S3 in the boost switch tube combination 112, the third switch tube S3 in each pulse width modulation period T2, and the turn-on time t of the third switch tube S3 in the T2 period are on2 The relationship satisfies the following formula:

[0078]

[0079] The set switch tube in the boost switch tube combination 112 can be the third switch tube S3 or the fourth switch tube S4. M2 in the above formula is the duty cycle of the third switch tube S3. The sum of the duty cycles of the third switch tube S3 and the fourth switch tube S4 is equal to 1. The duty cycle of the fourth switch tube S4 can also be used to represent the DC input voltage U in With AC output voltage U out The embodiment of the present disclosure does not limit this.

[0080] In this way, when the inverter modulation index λ is fixed at 1, the duty cycle of the switch tube can be set by adjusting the boost switch tube combination 112, so that the compressor drive circuit can play a boosting role, reduce the harmonic distortion rate, and still ensure that the output AC sine wave has a good waveform and a low harmonic distortion rate when outputting a low-amplitude AC voltage.

[0081] The driving method of the compressor driving circuit provided by the embodiment of the present disclosure controls the buck-boost circuit 11 to adjust the DC input voltage of the compressor driving circuit to the DC intermediate voltage; controls the inverter circuit to adjust the DC intermediate voltage to the AC output voltage of the compressor driving circuit; wherein the inverter modulation index of the inverter circuit is a fixed value equal to or slightly less than 1. Therefore, the embodiment of the present disclosure improves the driving method of the compressor driving circuit, so that the compressor driving circuit has the buck-boost function, thereby ensuring that the upper limit of the AC output voltage is not affected by the DC voltage input size provided by the power platform of the mobile device, and expanding the selection range of linear compressor models. At the same time, the inverter modulation index of the improved circuit is a fixed value equal to or slightly less than 1, and the amplitude of the AC output voltage can be adjusted by adjusting the duty cycle of the switch tube set in the boost switch tube combination 112 and the buck switch tube combination 111, and when outputting a low-amplitude AC voltage, the output AC sinusoidal wave waveform can still be ensured to be good and the harmonic distortion rate is low.

[0082] The embodiment of the present disclosure also provides a compressor driving circuit, which is driven by the driving method of the compressor driving circuit as described in the above embodiment. Therefore, the compressor driving circuit provided by the embodiment of the present disclosure has the beneficial effects described in the above embodiment, which will not be described in detail here. Figure 2 As shown, the buck-boost circuit 11 is electrically connected to the inverter circuit 12 .

[0083] Alternatively, if Figure 2 As shown, the inverter circuit 12 includes: an inverter bridge circuit 121 and an integration circuit 122, the inverter bridge circuit 121 is electrically connected to the integration circuit 122, and the inverter bridge circuit 121 is used to convert the DC intermediate voltage U dc Converted to AC intermediate voltage U m The integration circuit 122 is used to convert the AC intermediate voltage U m Adjust to AC output voltage U out ; Among them, the AC output voltage U out is a sinusoidal voltage.

[0084] Specifically, Figure 2 As shown, the fifth switch tube S5, the sixth switch tube S6, the seventh switch tube S7 and the eighth switch tube S8 in the inverter bridge circuit 121 form an H-bridge circuit. The inverter bridge circuit 121 has the function of converting direct current into alternating current, and can convert the DC intermediate voltage U output by the buck-boost circuit 11 into alternating current. dc Converted to AC intermediate voltage U m ,like Figure 3 As shown, the AC intermediate voltage U m After being input to the integration circuit 122, the integration circuit 122 converts the AC intermediate voltage U m Adjust to AC output voltage U out , AC output voltage U outThe sine wave voltage is used to drive the linear compressor, driving the piston fixed to the motor rotor to move at a specified frequency. By adjusting the AC output voltage U of the linear compressor drive circuit out The amplitude of can realize the control of the piston reciprocating stroke, thereby adjusting the input work, and then realizing the control of the cooling capacity, and achieving the purpose of regulating and controlling the temperature of the heat load. In addition, the specific structure and specific working principle of the inverter bridge circuit 121 and the integration circuit 122 are well known to those skilled in the art, and will not be discussed in detail here.

[0085] Optionally, the switch tubes in the buck-boost circuit 11 and / or the inverter circuit 12 are surface-mounted power MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors) of model IRHNA67160.

[0086] Mobile pulse tube refrigeration systems are used to cool detection devices in space-cooled infrared detection equipment and high-purity germanium detection equipment because of their advantages such as no mechanical vibration source at the cold end and long service life of the mechanical structure. Given the special use environment of mobile pulse tube refrigeration systems, they face many challenges. In the radiation environment where space-cooled infrared detection equipment and high-purity germanium detection equipment are used in actual applications, there are high-energy charged particles that affect the operation of the compressor drive circuit. When high-energy charged particles are incident on the compressor drive circuit, the energy deposited in the incident path is sufficient to cause the compressor drive circuit to degrade in performance or even lose its function. This is called a single-particle effect, which has a greater impact on the compressor drive circuit. The most common concerns are the single event latch-up (SEL) and single event upset (SEU) effects.

[0087] The single-particle latch-up effect refers to the PNPN alternation in the integrated circuit chip manufacturing process, which forms a switch tube structure. When a charged particle is incident, it can trigger its conduction. Due to the positive feedback characteristics of the switch tube, the switch tube reaches a self-sustaining state, that is, latching occurs. At this time, the current can reach the ampere level, causing the local temperature to rise. When the temperature exceeds a certain limit, it will cause permanent damage to the device.

[0088] The single particle upset effect is a state change caused by a single charged particle passing through a sensitive node of a device. The corresponding node voltage will change, and through diffusion in the external circuit, it may cause the state of the circuit to change. This effect is usually short-lived and will not cause damage to the circuit. Depending on the number of bits that flip the logic state, single particle upsets include single-bit upsets and multi-bit upsets. Single particle upsets are very harmful and can cause errors in the contents of storage cells, malfunctions in controllers, or CPU program runaway.

[0089] In mobile refrigeration systems, in order to achieve precise control of the cold end temperature, the linear compressor needs to be digitally controlled, so integrated circuits are inevitably required. For radiation environment application scenarios, the impact of single particle effects must be carefully considered. When a charged particle is incident on a material, the energy lost per unit path length is called linear energy transfer (LET). LET is usually normalized by the material density and the unit is MeV·cm 2 / mg, which represents the direct ionization ability of charged particles in the material. It is generally believed that particles with the same LET value have the same ability to produce single particle effects, so LET becomes a normalized measure of the ability of charged particles of different types and energies to produce single particle effects. For a certain device, the lowest LET value that can cause a single particle effect is called the LET threshold. In the embodiment of the present disclosure, the LET threshold of the device is set to be greater than 75MeV·cm 2 / mg.

[0090] The switch tube in the compressor drive circuit of the embodiment of the present disclosure adopts a surface-mounted power MOSFET of model IRHNA67160. This type of switch tube has a fast switching speed and can meet the LET threshold of more than 75 MeV·cm 2 / mg selection conditions.

[0091] It should be noted that the switch tubes in the buck-boost circuit 11 and the inverter circuit 12 can be set to use surface-mount packaged power MOSFETs with model number IRHNA67160, or the switch tube in the buck-boost circuit 11 can be set to use surface-mount packaged power MOSFETs with model number IRHNA67160, or the switch tube in the inverter circuit 12 can be set to use surface-mount packaged power MOSFETs with model number IRHNA67160.

[0092] The embodiment of the present disclosure also provides a compressor driving system, Figure 6The schematic diagram of the structure of a compressor drive system provided by an embodiment of the present disclosure includes a control circuit 2 and a compressor drive circuit 100 as described in the above embodiment. The compressor drive circuit 100 is electrically connected to a refrigeration system compressor 200 and is used to drive the refrigeration system compressor 200. Therefore, the compressor drive system provided by the embodiment of the present disclosure has the beneficial effects described in the above embodiment. The control circuit 2 is electrically connected to the compressor drive circuit 100, and the control circuit 2 is used to control the compressor drive circuit 100 to generate an AC output voltage U out .

[0093] Alternatively, if Figure 6 As shown, the control circuit 2 includes: a processor 21, a memory 24, a first gate drive chip 22 and a second gate drive chip 23. The processor 21 is electrically connected to the host computer 3, the memory 24, the first gate drive chip 22 and the second gate drive chip 23 respectively. The first gate drive chip 22 is electrically connected to the buck-boost circuit 11, and the second gate drive chip 23 is electrically connected to the inverter circuit 12. The processor 21 is used to drive the buck-boost circuit 11 through the first gate drive chip 22 according to the duty cycle information sent by the host computer 3, and is used to read the set sinusoidal pulse width table stored in the memory 24 to output a sinusoidal pulse width modulation signal, that is, an SPWM signal to the second gate drive chip 23, and drive the inverter circuit 12 through the second gate drive chip 23.

[0094] Specifically, the AC output voltage U can be set out With DC input voltage U in The ratio is α, and the host computer 3 determines the AC output voltage U required by the compressor. out And determine the size of the ratio α. For example, when the ratio α is less than When the ratio α is greater than When the voltage step-up / down circuit 11 is controlled to be in a voltage step-down state, the working principle of the voltage step-up / down circuit 11 is as described in the above embodiment and will not be repeated here.

[0095] Exemplarily, when the buck-boost circuit 11 is in the buck state, the duty cycle value of the third switch tube S3 in the boost switch tube combination 112 is set to 0, and the host computer 3 determines the duty cycle value of the first switch tube S1 in the buck switch tube combination 111; when the buck-boost circuit 11 is in the boost state, the duty cycle value of the first switch tube S1 in the buck switch tube combination 111 is set to 0, and the host computer 3 determines the duty cycle value of the third switch tube S3 in the boost switch tube combination 112. The host computer 3 sends the information of the duty cycle of the switch tube set in the boost switch tube combination 112 or the duty cycle of the switch tube set in the buck switch tube combination 111 to the processor 21 through a communication interface, such as an RS422 interface, and the processor 21 drives the buck-boost circuit 11 through the first gate drive chip 22 to make it in the boost state or the buck state. At the same time, the processor 21 can output a sinusoidal pulse width modulation signal, i.e., an SPWM signal, to the second gate drive chip 23. The second gate drive chip 23 completes the control of the H-bridge circuit composed of the switch tubes in the inverter circuit 12, so that the inverter circuit 12 outputs the sinusoidal voltage U required for compressor driving. out .

[0096] In the embodiment of the present disclosure, the inverter modulation index λ is set to a fixed value equal to or slightly less than 1, so there is no need to recalculate the sine pulse width table. The required sine pulse width table is calculated in the design stage and stored in the memory 24. Figure 3 It can be seen from the related theory of sinusoidal width modulation shown that the sinusoidal pulse width table needs to store the time width of each segmented square wave pulse. The processor 21 reads the stored sinusoidal pulse width table from the memory 24, and outputs a sinusoidal pulse width modulation signal, i.e., an SPWM signal, to the second gate drive chip 23 according to the set sinusoidal pulse width table, and drives the inverter circuit 12 through the second gate drive chip 23. Since the inverter modulation index λ is a fixed value equal to or slightly less than 1, it is not necessary to calculate and update the sinusoidal pulse width table corresponding to the inverter modulation index λ during the driving process, and the storage space occupied by the duty cycle of the switch tube set in the boost switch tube combination 112 and the duty cycle of the switch tube set in the buck switch tube combination 111 is much smaller than the storage space required for calculating and updating the sinusoidal pulse width table, which greatly reduces the storage space requirement of the compressor drive system for the memory 24.

[0097] Optionally, the processor 21 uses an anti-fuse FPGA (Field Programmable Gate Array) of model A54SX72A-CQ208B, and the memory 24 uses a PROM (Programmable read-only memory) of model HS1-6664RH-Q.

[0098] In order to achieve better modulation effects and reduce the size of the filter, the compressor often requires a higher carrier ratio, which also means that the number of elements contained in the required sinusoidal pulse width table will be large, ranging from hundreds to thousands in actual applications. If the sinusoidal pulse width table corresponding to the inverter modulation index needs to be calculated and updated during the operation of the compressor, a large amount of processor 21 resources will be consumed, resulting in the need for a high-performance processor 21 to perform sinusoidal pulse width table update calculations when the compressor drive system is used in a high-energy particle radiation environment. The DSP (Digital Signal Processing) and SRAM (Static Random-Access Memory) type FPGAs that meet the computing power used in the prior art are expensive and have weak single-particle flip resistance. When the compressor drive system is applied in a near-Earth space radiation environment, DSP and SRAM type FPGAs with radiation resistance indicators can meet the LET threshold of more than 75MeV·cm for single-particle locking. 2 / mg condition, but its single-particle upset threshold is often lower.

[0099] In addition, the compressor working in the refrigeration system needs to run uninterruptedly when it is turned on, which requires continuous real-time control. It is impossible to reduce the impact of single-particle upsets by remote verification and feedback. If there is an error in the sinusoidal pulse width modulation signal, the quality of the sinusoidal waveform will be reduced, which will affect the refrigeration efficiency and even burn the linear compressor. Therefore, the sinusoidal pulse width modulation signal has the characteristics of high real-time performance and does not allow errors. Under radiation conditions, related programs and circuits need to be designed with triple-mode redundancy or multi-mode redundancy, which will significantly increase the cost of software and hardware development.

[0100] The processor 21 of the disclosed embodiment adopts the A54SX72A-CQ208B anti-fuse FPGA with single particle immunity, and the PROM memory 24 of the HS1-6664RH-Q model can directly read the sine pulse width table information, which is not affected by single particle upset. Therefore, the processor 21 chip used in the disclosed embodiment has low performance, occupies less data calculation and processing resources, and the memory 24 is not affected by single particle upset, which saves the software and hardware costs for sine pulse width modulation and has high reliability.

[0101] Optionally, the first gate driving chip 22 and / or the second gate driving chip 23 adopts a high-speed MOSFET driving chip of model IR2110L4SCS.

[0102] Specifically, the gate driver chip uses a high-speed MOSFET driver chip of model IR2110L4SCS and is used in conjunction with a switch tube of the surface-mounted power MOSFET model of IRHNA67160, which meets the selection condition that the LET threshold for single-particle lock-in resistance is greater than 75MeV·cm2 / mg. It should be noted that the first gate driver chip 22 and the second gate driver chip 23 can both use a high-speed MOSFET driver chip of model IR2110L4SCS, or the first gate driver chip 22 can use a high-speed MOSFET driver chip of model IR2110L4SCS or the second gate driver chip 23 can use a high-speed MOSFET driver chip of model IR2110L4SCS.

[0103] Specifically, Figure 6 As shown, after the DC voltage provided by the mobile device power platform enters the buck-boost circuit, the converted DC voltage is obtained, and then after passing through the inverter circuit, the AC voltage required by the refrigeration system compressor is obtained. The control circuit 2 is used to control the on and off of the switch tube in the linear compressor drive circuit to complete the AC voltage amplitude adjustment function. The open-loop / closed-loop control strategy is determined by the host computer 2. The host computer 2 sends the required parameter setting values, duty cycle M1, that is, the buck coefficient, and duty cycle M2, that is, the boost coefficient, to the anti-fuse FPGA in the control circuit 2 through the RS422 communication interface. The anti-fuse FPGA completes the control of the power MOSFET in the DC buck-boost circuit through the gate drive chip.

[0104] The driving method, driving circuit and driving system of the compressor driving circuit provided by the embodiment of the present disclosure improve the driving method of the compressor driving circuit, so that the compressor driving circuit has the function of step-up and step-down, thereby ensuring that the upper limit of the AC output voltage is not affected by the DC voltage input size provided by the mobile device power platform, and expanding the selection range of linear compressor models. At the same time, the inverter modulation index of the improved circuit is equal to or slightly less than 1. It is only necessary to adjust the duty cycle of the switch tube set in the boost switch tube combination and the buck switch tube combination to adjust the amplitude of the AC output voltage. When outputting a low-amplitude AC voltage, it can still ensure that the output AC sine wave waveform is good and the harmonic distortion rate is low.

[0105] Mobile pulse tube refrigeration systems are used for cooling detection devices of space-cooled infrared detection equipment and high-purity germanium detection equipment due to their advantages such as no mechanical vibration source at the cold end and long service life of the mechanical structure. In view of the special use environment of the mobile pulse tube refrigeration system, it faces many challenges. In view of the shortcomings of the prior art, the disclosed embodiment proposes a linear compressor drive control scheme for a mobile pulse tube refrigeration system for use in a high-energy particle radiation environment. The purpose is to be applied to a high-energy particle radiation environment to avoid the influence of single particle flips on sinusoidal pulse width modulation; to avoid the system's dependence on high-performance data processing chips and complex calculation programs, and to reduce hardware and software development costs. The problem of the limited amplitude of the DC input voltage provided by the power platform of the mobile device is solved, which in turn causes the AC output voltage amplitude to be limited and cannot reach the rated supply voltage of the linear compressor. The problem of harmonic distortion caused by low inverter modulation when outputting low-amplitude AC voltage is solved.

[0106] Thus, a novel linear compressor driving circuit and a matching AC voltage amplitude control method are realized, the required processor chip performance is low, the occupied data calculation and processing resources are small, the software and hardware costs for sinusoidal pulse width modulation are saved, and the reliability is high; the upper limit of the AC output voltage is not affected by the DC voltage input size provided by the mobile device power platform, and is suitable for linear compressors with large electrical impedance; when outputting low-amplitude AC voltage, the output AC sinusoidal wave waveform can still be guaranteed to be good and the harmonic distortion rate is low.

[0107] It should be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusions, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0108] The above are only specific embodiments of the present disclosure, so that those skilled in the art can understand or implement the present disclosure. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure will not be limited to these embodiments herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A driving method for a compressor driving circuit, characterized in that: The compressor driving circuit includes a buck-boost circuit and an inverter circuit, and the buck-boost circuit includes a boost switch tube combination and a buck switch tube combination; wherein the switch states of the two switch tubes in the boost switch tube combination are complementary, and the switch states of the two switch tubes in the buck switch tube combination are complementary; The driving method of the compressor driving circuit comprises: Controlling the buck-boost circuit to adjust the DC input voltage of the compressor drive circuit to a DC intermediate voltage; The inverter circuit is controlled to adjust the DC intermediate voltage to the AC output voltage of the compressor drive circuit; wherein the inverter modulation index of the inverter circuit is a fixed value equal to 1, and the sinusoidal AC intermediate voltage U m The time width calculation formula of each segmented square pulse in the first half of the cycle is: δ i represents the time width of the pulse of the i-th segment, λ is the inverter modulation degree, T is the sine wave period, and N is the number of segments in half a sine wave period; Based on the symmetry of the sine wave, the time width calculation formula for each segmented square pulse in the second half of the sine wave is: The required sinusoidal pulse width table is calculated in the design stage and stored in a memory, which uses a PROM memory of the HS1-6664RH-Q model; Set the AC output voltage U out With DC input voltage U in The ratio of is α, and the buck-boost state of the buck-boost circuit is determined based on the ratio α, wherein when the ratio α is less than When the ratio α is greater than When the voltage is increased or decreased, the voltage-boosting circuit is controlled to be in a voltage-boosting state; Wherein, when the buck-boost circuit is in a buck state, the switch tube electrically connected to the negative end of the DC power in the boost switch tube combination is controlled to be turned off, the switch tube on the DC positive end transmission line in the boost switch tube combination is controlled to be turned on, and the duty cycle of the switch tube in the buck switch tube combination is controlled to be set to adjust the AC output voltage; When the buck-boost circuit is in a boost state, the switch tube electrically connected to the negative end of the DC power in the buck switch tube combination is controlled to be turned off, the switch tube on the DC positive end transmission line in the buck switch tube combination is controlled to be turned on, and the duty cycle of the switch tube in the boost switch tube combination is controlled to be set to adjust the AC output voltage.

2. The driving method of the compressor driving circuit according to claim 1, characterized in that: The buck-boost circuit further includes a first inductor and a first capacitor, the buck switch tube combination includes a first switch tube and a second switch tube, and the boost switch tube combination includes a third switch tube and a fourth switch tube, the first switch tube, the first inductor and the fourth switch tube are sequentially connected in series between the positive end of the DC input voltage and the positive end of the DC intermediate voltage, the second switch tube is connected in series between the first end of the first inductor and the negative end of the DC input voltage, the third switch tube is connected in series between the second end of the first inductor and the negative end of the DC input voltage, the first capacitor is connected in series between the positive end of the DC intermediate voltage and the negative end of the DC intermediate voltage, and the negative end of the DC input voltage is electrically connected to the negative end of the DC intermediate voltage; When the buck-boost circuit is in a buck state, the driving method of the compressor driving circuit includes: The third switch tube is controlled to be normally closed and the fourth switch tube is controlled to be normally open, and the first switch tube and the second switch tube are controlled to be alternately turned on; wherein the set switch tube in the step-down switch tube combination is the first switch tube or the second switch tube.

3. The driving method of the compressor driving circuit according to claim 2, characterized in that: When the buck-boost circuit is in a boost state, the driving method of the compressor driving circuit includes: The second switch tube is controlled to be normally closed and the first switch tube is controlled to be normally open, and the third switch tube and the fourth switch tube are controlled to be alternately turned on; wherein the set switch tube in the boost switch tube combination is the third switch tube or the fourth switch tube.

4. A compressor driving circuit, characterized in that: Driven by the driving method of the compressor driving circuit according to any one of claims 1 to 3, the buck-boost circuit is electrically connected to the inverter circuit.

5. The compressor driving circuit according to claim 4, characterized in that: The inverter circuit comprises: An inverter bridge circuit and an integration circuit, wherein the inverter bridge circuit is electrically connected to the integration circuit, the inverter bridge circuit is used to convert the DC intermediate voltage into an AC intermediate voltage, and the integration circuit is used to adjust the AC intermediate voltage to the AC output voltage; wherein the AC output voltage is a sinusoidal wave voltage.

6. The compressor driving circuit according to claim 4, characterized in that: The switch tube in the buck-boost circuit and / or the inverter circuit adopts a surface-mounted power MOSFET of model IRHNA67160.

7. A compressor drive system, characterized in that: It comprises a control circuit and a compressor driving circuit as described in any one of claims 4 to 6, wherein the control circuit is electrically connected to the compressor driving circuit, and the control circuit is used to control the compressor driving circuit to generate the AC output voltage.

8. The compressor drive system according to claim 7, characterized in that: The control circuit comprises: A processor, a memory, a first gate drive chip and a second gate drive chip, wherein the processor is electrically connected to a host computer, the memory, the first gate drive chip and the second gate drive chip respectively, the first gate drive chip is electrically connected to the buck-boost circuit, and the second gate drive chip is electrically connected to the inverter circuit; The processor is used to drive the buck-boost circuit through the first gate drive chip according to the duty cycle information sent by the host computer, and is used to read the set sinusoidal pulse width table stored in the memory to output a sinusoidal pulse width modulation signal to the second gate drive chip, and drive the inverter circuit through the second gate drive chip.

9. The compressor drive system according to claim 8, characterized in that: The processor adopts an anti-fuse FPGA of the A54SX72A-CQ208B model, and the memory adopts a PROM memory of the HS1-6664RH-Q model.

10. The compressor drive system according to claim 8, characterized in that: The first gate driving chip and / or the second gate driving chip adopts a high-speed MOSFET driving chip of model IR2110L4SCS.

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