Single-phase staggered PFC heat pump drive control device

Abstract

The utility model discloses a single-phase staggered PFC heat pump drive control device, and a PFC drive module comprises a first PFC drive unit and a second PFC drive unit connected in parallel with the first PFC drive unit. The rectifier bridge is used for accessing alternating current, converting the alternating current into direct current and inputting the direct current into the PFC driving module; the sampling module is used for collecting actual operation data and inputting the actual operation data into the MCU module; the MCU module is used for controlling the first PFC driving unit and the second PFC driving unit to work alternately; according to the utility model, the MCU module controls the working states of the switch tubes in the first PFC driving unit and the second PFC driving unit in a staggered manner, so that the two switch tubes work in a staggered manner, and each switch tube only needs to bear half of the total input current, thereby effectively reducing the electrical stress of each switch tube, prolonging the service life, and reducing the cost. And the use of the switch tube with relatively low cost is realized.

Description

Technical Field

[0001] The utility model relates to the field of heat pump drive control, in particular to a single-phase interleaved PFC heat pump drive control device. Background Art

[0002] In heat pump systems below 5P (horsepower), the use of a single switch tube plus a reactor for power factor correction (PFC) can meet the needs. However, when the system power exceeds 5P, the traditional single switch tube solution will encounter challenges, mainly because the cost of high-power switch tubes has increased significantly, and the required reactor is bulky and takes up too much space. As the system power increases, the current that a single switch tube needs to withstand also increases, which not only increases the electrical stress of the switch tube, but may also affect its life and reliability. Utility Model Content

[0003] In order to solve the above technical problems, the utility model proposes a single-phase interleaved PFC heat pump drive control device, comprising:

[0004] The PFC driving module comprises a first PFC driving unit and a second PFC driving unit connected in parallel with the first PFC driving unit;

[0005] The rectifier bridge is used to receive AC power and convert it into DC power before inputting it into the PFC drive module;

[0006] Sampling module, used to collect actual operation data and input it into the MCU module;

[0007] A driver connected to the output end of the PFC driver module;

[0008] The MCU module is used to control the first PFC drive unit and the second PFC drive unit to work alternately, and dynamically adjust the duty cycle instructions of the first PFC drive unit and the second PFC drive unit when working according to actual operation data; and is also used to send a PWM duty cycle drive signal to the driver;

[0009] The driver is used to drive the operation of the motor according to the PWM duty cycle driving signal sent by the MCU module.

[0010] Furthermore, the actual operation data includes: an actual voltage value output by the rectifier bridge, an actual output voltage value and an actual output current value of the PFC drive module, and an actual output current value of the second PFC drive unit.

[0011] Furthermore, the MCU module also includes a first PI regulator for issuing a duty cycle instruction to the first PFC drive unit, and a second PI regulator for issuing a duty cycle instruction to the second PFC drive unit.

[0012] Furthermore, the MCU module includes: a first timing module or a second timing module; the first timing module includes: a TIM4 timer and a TIM7 timer; the second timing module includes a TIM5 timer.

[0013] Further, the initial value of the TIM4 timer is 0, and the timing period is 1000; the initial value of the TIM7 timer is 1000, and the timing period is 1000;

[0014] The counting directions of the TIM4 timer and the TIM7 timer are opposite.

[0015] Further, within one PWM cycle, when the count value of the TIM4 timer is greater than the output value of the first PI regulator, the drive pin of the first PFC drive unit corresponding to the IGBT outputs a high level, and when the count value of the TIM4 timer is less than the output value of the first PI regulator, the drive pin of the first PFC drive unit corresponding to the IGBT outputs a low level; within one PWM cycle, when the count value of the TIM7 timer is greater than the second PI regulator, the drive pin of the second PFC drive unit corresponding to the IGBT outputs a high level, and when the count value of the TIM7 timer is less than the output value of the second PI regulator, the drive pin of the second PFC drive unit corresponding to the IGBT outputs a low level.

[0016] Further, when the MCU module includes a first timing module, the MCU module controls the TIM4 timer and the TIM7 timer to start simultaneously, and controls the duty cycle instruction issued by the first PI regulator to the first PFC drive unit through the count of the TIM4 timer, and controls the duty cycle instruction issued by the second PI regulator to the second PFC drive unit through the count of the TIM7 timer, so that the first PFC drive unit and the second PFC drive unit work alternately.

[0017] Furthermore, the initial value of the TIM5 timer count value is 0, and the count period is 1000; when the TIM5 timer count value increases to 1000, it continues to decrease from 1000, and when it decreases to 0, it continues to increase to 1000, and repeats this cycle.

[0018] Further, within a PWM cycle, when the TIM5 timer is in the rising counting stage and the output value of the first PI regulator is equal to the count value of the TIM5 timer, the drive pin of the first PFC drive unit corresponding to the IGBT outputs a high level, and when the TIM5 timer is in the falling counting stage and the output value of the first PI regulator is equal to the count value of the TIM5 timer, the drive pin of the first PFC drive unit corresponding to the IGBT outputs a low level; within a PWM cycle, when the TIM5 timer is in the rising counting stage and the output value of the second PI regulator is equal to the count value of the TIM5 timer, the drive pin of the second PFC drive unit corresponding to the IGBT outputs a low level, and when the TIM5 timer is in the falling counting stage and the output value of the second PI regulator is equal to the count value of the TIM5 timer, the drive pin of the second PFC drive unit corresponding to the IGBT outputs a high level.

[0019] Further, when the MCU module includes a second timing module, the MCU module controls the outputs of the first PI regulator and the second PI regulator through the count of the TIM5 timer, so that the first PFC driving unit and the second PFC driving unit work alternately.

[0020] Compared with the prior art, the utility model has at least the following beneficial effects:

[0021] (1) In the present invention, the PFC drive module includes a first PFC drive unit and a second PFC drive unit connected in parallel with the first PFC drive unit; a rectifier bridge, used to receive AC power and convert it into DC power and then input it into the PFC drive module; a sampling module, used to collect actual operation data and input it into the MCU module; the MCU module is used to control the first PFC drive unit and the second PFC drive unit to work alternately; that is, the MCU module in the present invention controls the working state of the switch tubes in the first PFC drive unit and the second PFC drive unit in an interlaced manner, so that the two switch tubes work alternately, and each switch tube only needs to bear half of the total input current, which effectively reduces the electrical stress of each switch tube, prolongs the service life, and realizes the use of relatively low-cost switch tubes;

[0022] (2) In the present invention, by interleaving the working states of the switch tubes in the first PFC drive unit and the second PFC drive unit, the ripple of the input current can be significantly reduced and the power factor can be improved. Due to the reduction of the input current ripple, the inductance value of the required inductor is reduced, and the actual volume of the inductor will also be reduced. At the same time, the interleaved operation can distribute the heat load on more switch tubes, which is beneficial to heat dissipation, reduces the temperature rise of a single device, and improves the long-term reliability and life of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural diagram of a single-phase interleaved PFC heat pump drive control device;

[0024] Figure 2 It is the control structure diagram of PI regulator;

[0025] Figure 3 is a circuit diagram corresponding to the first PFC driving unit;

[0026] Figure 4 is a circuit diagram corresponding to the second PFC driving unit. DETAILED DESCRIPTION

[0027] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0028] Embodiment 1

[0029] In order to reduce the cost of switch tubes in high-power heat pump systems, Figure 1 As shown, the utility model proposes a single-phase interleaved PFC heat pump drive control device, comprising:

[0030] The PFC driving module comprises a first PFC driving unit and a second PFC driving unit connected in parallel with the first PFC driving unit;

[0031] Rectifier bridge, used to receive 220V AC power and convert it into DC power before inputting into the PFC drive module;

[0032] The sampling module is used to collect actual operation data and input it into the MCU module; the actual operation data includes: the actual voltage value of the rectifier bridge output, the actual output voltage value of the PFC drive module, the actual output current value of the second PFC drive unit and the actual output current value of the PFC drive module. The actual output current value of the PFC drive module is the actual output current value of the loop formed by the first PFC drive unit and the second PFC drive unit.

[0033] It should be explained that the sampling module includes: a first sampling unit 1, a second sampling unit 2 and a third sampling unit 3 (ie Figure 1 1, 2, 3). Among them:

[0034] The first sampling unit 1 is used to collect the actual voltage value output by the rectifier bridge;

[0035] The second sampling unit 2 is used to collect the actual output current value and the actual output current value of the PFC driving module;

[0036] The third sampling unit 3 is used to collect the actual output current value of the second PFC driving unit.

[0037] A driver connected to the output end of the PFC driver module;

[0038] The MCU module further includes a first PI regulator for issuing a duty cycle instruction to the first PFC drive unit, and a second PI regulator for issuing a duty cycle instruction to the second PFC drive unit.

[0039] The MCU module further includes: a first timing module or a second timing module; the first timing module includes: a TIM4 timer and a TIM7 timer; the second timing module includes a TIM5 timer.

[0040] The initial value of the TIM4 timer is 0, and the timing period is 1000; the initial value of the TIM7 timer is 1000, and the timing period is 1000;

[0041] The counting directions of the TIM4 timer and the TIM7 timer are opposite.

[0042] In one PWM cycle, when the count value of the TIM4 timer is greater than the output value of the first PI regulator, the drive pin of the first PFC drive unit corresponding to the IGBT outputs a high level, and when the count value of the TIM4 timer is less than the output value of the first PI regulator, the drive pin of the first PFC drive unit corresponding to the IGBT outputs a low level; in one PWM cycle, when the count value of the TIM7 timer is greater than the second PI regulator, the drive pin of the second PFC drive unit corresponding to the IGBT outputs a high level, and when the count value of the TIM7 timer is less than the output value of the second PI regulator, the drive pin of the second PFC drive unit corresponding to the IGBT outputs a low level.

[0043] It should be noted that the initial value of TIM4 is 0, while the initial value of TIM7 is set to 1000. This means that the starting points of the two timers are exactly one cycle length (1000 counting units) apart. After the device is running, TIM4 starts counting up from 0 until it reaches 1000, and at the same time, TIM7 starts counting down from 1000 until it reaches 0. This process ensures that the working states of the two are exactly staggered in time, forming an interlaced state. When TIM4 counts to 1000, its counter is reset to 0 and immediately starts counting up for the next cycle; and when TIM7 counts to 0, it is also reset to 1000 and starts a new decrement cycle. This design ensures that at the beginning of each cycle, TIM4 and TIM7 are always in opposite counting directions, maintaining an electrical angle difference of 180 degrees, and realizing the interlaced operation of the two PFC drive units. In addition, since the switching actions of the two PFC drive units are staggered by 180 electrical degrees, the ripples in the input current can offset each other, thereby improving the power factor.

[0044] The initial value of the TIM5 timer count value is 0, and the count period is 1000; when the TIM5 timer count value increases to 1000, it continues to decrease from 1000, and when it decreases to 0, it continues to increase to 1000, and repeats this cycle.

[0045] In one PWM cycle, when the TIM5 timer is in the rising counting stage and the output value of the first PI regulator is equal to the count value of the TIM5 timer, the drive pin of the first PFC drive unit corresponding to the IGBT outputs a high level, and when the TIM5 timer is in the falling counting stage and the output value of the first PI regulator is equal to the count value of the TIM5 timer, the drive pin of the first PFC drive unit corresponding to the IGBT outputs a low level; in one PWM cycle, when the TIM5 timer is in the rising counting stage and the output value of the second PI regulator is equal to the count value of the TIM5 timer, the drive pin of the second PFC drive unit corresponding to the IGBT outputs a low level, and when the TIM5 timer is in the falling counting stage and the output value of the second PI regulator is equal to the count value of the TIM5 timer, the drive pin of the second PFC drive unit corresponding to the IGBT outputs a high level.

[0046] In this embodiment, when only one timer TIM5 is used, its initial value is set to 0, which means that the count starts from zero. The period value of TIM5 is also set to 1000 counting units, which is consistent with the period of each timer in the previous method, ensuring the matching of the control period. TIM5 adopts a continuous increase and decrease counting mode, which means that after counting from 0 to 1000, it will immediately start to decrease from 1000 back to 0, and then increase from 0 again, and so on. This mode ensures the continuity of the control signal and provides a basis for interleaved control.

[0047] The MCU module is used to control the first PFC drive unit and the second PFC drive unit to work alternately, and dynamically adjust the duty cycle instructions of the first PFC drive unit and the second PFC drive unit when working according to actual operation data; and is also used to send a PWM duty cycle drive signal to the driver;

[0048] In this embodiment, the MCU module adopts a digital signal processor DSP (TMS320F28034).

[0049] When the MCU module includes a first timing module, the MCU module controls the TIM4 timer and the TIM7 timer to start simultaneously, and controls the duty cycle instruction issued by the first PI regulator to the first PFC drive unit through the count of the TIM4 timer, and controls the duty cycle instruction issued by the second PI regulator to the second PFC drive unit through the count of the TIM7 timer, so that the first PFC drive unit and the second PFC drive unit work alternately.

[0050] Figure 2 In: Uo* is a given reference voltage (360V), Ui* is the actual voltage value output by the rectifier bridge, Uo is the actual output voltage value of the PFC driver module (i.e., the voltage value output after the first PFC driver unit and the second PFC driver unit work together), Um represents the maximum amplitude of the rectifier bridge output, il represents the actual output current value of the first PFC driver unit or the second PFC driver unit (the actual output current value of the first PFC driver unit is the difference between the actual output current value of the PFC driver module and the actual output current value of the second PFC driver unit).

[0051] In this embodiment, the control process of the first PI regulator is as follows: Figure 2 As shown (in this process, il represents the actual output current value of the first PFC driving unit):

[0052] 1. Compare Uo and Uo*, and send the error to the first-order inertial PI regulator (PI1 in the figure). The output of PI1 is the given current reference value Il*;

[0053] 2. Calculator: Multiply Ui* by 1 / Um to get the phase ui* and input it into the multiplier;

[0054] 3. Multiplier: multiply the phase ui* by the given current reference value Il* to obtain il*;

[0055] 4. Subtract il* from il to get the current error value, which is output to the second first-order inertial PI regulator (PI2 in the figure);

[0056] 5. Comparator: convert the output of PI2 to obtain the corresponding digital quantity, and output the corresponding pwm signal to the IGBT module in the first PFC drive unit by comparing the ramp function with the digital quantity.

[0057] In this embodiment, the control process of the second PI regulator is as follows: Figure 2 As shown (in this process, il represents the actual output current value of the second PFC drive unit):

[0058] 1. Compare Uo and Uo*, and send the error to the first-order inertial PI regulator (PI1 in the figure). The output of PI1 is the given current reference value Il*;

[0059] 2. Calculator: Multiply Ui* by 1 / Um to get the phase ui* and input it into the multiplier;

[0060] 3. Multiplier: multiply the phase ui* by the given current reference value Il* to obtain il*;

[0061] 4. Subtract il* from il to get the current error value, which is output to the second first-order inertial PI regulator (PI2 in the figure);

[0062] 5. Comparator: Convert the output of PI2 to obtain the corresponding digital quantity, and output the corresponding PWM signal to the IGBT module in the second PFC drive unit by comparing the ramp function with the digital quantity.

[0063] When the MCU module includes a second timing module, the MCU module controls the outputs of the first PI regulator and the second PI regulator through the count of the TIM5 timer, so that the first PFC driving unit and the second PFC driving unit work alternately.

[0064] The driver is used to drive the operation of the motor according to the PWM duty cycle driving signal sent by the MCU module.

[0065] In this embodiment, Figure 3 , Figure 4 Respectively represent the circuit diagram corresponding to the first PFC drive unit and the circuit diagram corresponding to the second PFC drive unit. Wherein:

[0066] Figure 3 In the figure: DBV- and DBV+ refer to the output ends of the rectifier bridge; U-AC is electrically connected to the MCU module; DC-S is electrically connected to the MCU module; DC+ is the output of the first PFC drive unit.

[0067] Figure 4 In the figure: DBV+ is connected to the first PFC drive unit; DC+ is the output of the second PFC drive unit; PFC-ISI represents the sampling point of the actual output current value of the second PFC drive unit; PFC-INA is used to access the PWM duty cycle drive signal issued by the MCU module.

[0068] In the utility model, the PFC drive module includes a first PFC drive unit and a second PFC drive unit connected in parallel with the first PFC drive unit; a rectifier bridge, used for connecting AC power and converting it into DC power and then inputting it into the PFC drive module; a sampling module, used for collecting actual operation data and inputting it into the MCU module; the MCU module is used for controlling the first PFC drive unit and the second PFC drive unit to work alternately; that is, the MCU module in the utility model controls the working state of the switch tubes in the first PFC drive unit and the second PFC drive unit in an interlaced manner, so that the two switch tubes work alternately, and each switch tube only needs to bear half of the total input current, which effectively reduces the electrical stress of each switch tube, prolongs the service life, and realizes the use of relatively low-cost switch tubes.

[0069] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back...) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0070] In addition, in the present invention, the descriptions of "first", "second", "one", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0071] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0072] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

Claims

1. A single-phase interleaved PFC heat pump drive control device, characterized in that: include: The PFC driving module comprises a first PFC driving unit and a second PFC driving unit connected in parallel with the first PFC driving unit; The rectifier bridge is used to receive AC power and convert it into DC power before inputting it into the PFC drive module; Sampling module, used to collect actual operation data and input it into the MCU module; A driver connected to the output end of the PFC driver module; The MCU module is used to control the first PFC drive unit and the second PFC drive unit to work alternately, and dynamically adjust the duty cycle instructions of the first PFC drive unit and the second PFC drive unit when working according to actual operation data; and is also used to send a PWM duty cycle drive signal to the driver; The driver is used to drive the operation of the motor according to the PWM duty cycle driving signal sent by the MCU module.

2. A single-phase interleaved PFC heat pump drive control device according to claim 1, characterized in that: The actual operation data includes: an actual voltage value output by the rectifier bridge, an actual output voltage value and an actual output current value of the PFC drive module, and an actual output current value of the second PFC drive unit.

3. A single-phase interleaved PFC heat pump drive control device according to claim 2, characterized in that: The MCU module further includes a first PI regulator for issuing a duty cycle instruction to the first PFC drive unit, and a second PI regulator for issuing a duty cycle instruction to the second PFC drive unit.

4. A single-phase interleaved PFC heat pump drive control device according to claim 3, characterized in that: The MCU module includes: a first timing module or a second timing module; the first timing module includes: a TIM4 timer and a TIM7 timer; the second timing module includes a TIM5 timer.

5. A single-phase interleaved PFC heat pump drive control device according to claim 4, characterized in that: The initial value of the TIM4 timer is 0, and the timing period is 1000; the initial value of the TIM7 timer is 1000, and the timing period is 1000; The counting directions of the TIM4 timer and the TIM7 timer are opposite.

6. A single-phase interleaved PFC heat pump drive control device according to claim 5, characterized in that: In one PWM cycle, when the count value of the TIM4 timer is greater than the output value of the first PI regulator, the drive pin of the first PFC drive unit corresponding to the IGBT outputs a high level, and when the count value of the TIM4 timer is less than the output value of the first PI regulator, the drive pin of the first PFC drive unit corresponding to the IGBT outputs a low level; in one PWM cycle, when the count value of the TIM7 timer is greater than the second PI regulator, the drive pin of the second PFC drive unit corresponding to the IGBT outputs a high level, and when the count value of the TIM7 timer is less than the output value of the second PI regulator, the drive pin of the second PFC drive unit corresponding to the IGBT outputs a low level.

7. A single-phase interleaved PFC heat pump drive control device according to claim 6, characterized in that: When the MCU module includes a first timing module, the MCU module controls the TIM4 timer and the TIM7 timer to start simultaneously, and controls the duty cycle instruction issued by the first PI regulator to the first PFC drive unit through the count of the TIM4 timer, and controls the duty cycle instruction issued by the second PI regulator to the second PFC drive unit through the count of the TIM7 timer, so that the first PFC drive unit and the second PFC drive unit work alternately.

8. A single-phase interleaved PFC heat pump drive control device according to claim 4, characterized in that: The initial value of the TIM5 timer count value is 0, and the count period is 1000; when the TIM5 timer count value increases to 1000, it continues to decrease from 1000, and when it decreases to 0, it continues to increase to 1000, and repeats this cycle.

9. A single-phase interleaved PFC heat pump drive control device according to claim 8, characterized in that: In one PWM cycle, when the TIM5 timer is in the rising counting stage and the output value of the first PI regulator is equal to the count value of the TIM5 timer, the drive pin of the first PFC drive unit corresponding to the IGBT outputs a high level, and when the TIM5 timer is in the falling counting stage and the output value of the first PI regulator is equal to the count value of the TIM5 timer, the drive pin of the first PFC drive unit corresponding to the IGBT outputs a low level; in one PWM cycle, when the TIM5 timer is in the rising counting stage and the output value of the second PI regulator is equal to the count value of the TIM5 timer, the drive pin of the second PFC drive unit corresponding to the IGBT outputs a low level, and when the TIM5 timer is in the falling counting stage and the output value of the second PI regulator is equal to the count value of the TIM5 timer, the drive pin of the second PFC drive unit corresponding to the IGBT outputs a high level.

10. A single-phase interleaved PFC heat pump drive control device according to claim 9, characterized in that: When the MCU module includes a second timing module, the MCU module controls the outputs of the first PI regulator and the second PI regulator through the count of the TIM5 timer, so that the first PFC driving unit and the second PFC driving unit work alternately.

Images