A control method of a single-stage architecture sub-power supply

Abstract

The application provides a control method of a single-stage architecture partial capacity power supply, which comprises the following steps: comparing and calculating a voltage reference value and an actual voltage value of a battery cell to obtain a current reference value of the battery cell; comparing and calculating the current reference value of the battery cell and a charging and discharging current value of the single-stage architecture partial capacity power supply to obtain a duty cycle; calculating a first additional mode duration and a second additional mode duration through the voltage value of the battery cell, a high-voltage DC bus voltage, the charging and discharging current value of the single-stage architecture partial capacity power supply and the duty cycle; and performing phase shift control on a high-voltage side switching network based on the first additional mode duration, the second additional mode duration and the duty cycle, and changing a voltage gain of the partial capacity power supply through PWM control on a current doubling rectification switching network to realize natural bidirectional energy flow and zero voltage turn-on of all switching tubes.

Description

Technical Field

[0001] The present invention relates to the field of power electronics technology, and in particular to a control method for a single-stage architecture capacity-dividing power supply. Background Art

[0002] The rapid expansion of the new energy vehicle industry has driven an annual increase in installed power battery capacity, resulting in a significant volume of retired power batteries requiring disposal each year. The cascaded reuse of retired power batteries not only reduces environmental pollution, but also avoids resource waste and maximizes economic benefits. A key step in the cascaded reuse of retired power batteries is capacity grading, which involves repeatedly charging and discharging them to assess their remaining capacity.

[0003] Traditional capacity-divided power supply equipment mostly adopts a two-stage architecture, that is, an LLC resonant converter + Buck converter solution. Compared with a single-stage architecture, a two-stage architecture requires more devices, making it difficult to improve the efficiency and power density of the device.

[0004] Although in recent years, existing technologies have proposed a single-stage architecture split-capacity power supply based on a phase-shifted full-bridge converter, this power supply cannot achieve natural bidirectional power flow. That is, each time the battery charge and discharge state switches, the switch tube drive logic needs to be changed, and the energy flow direction cannot be switched online, thus failing to meet the performance index requirements of transient regulation. Summary of the Invention

[0005] The present invention provides a control method for a single-stage architecture divided-capacity power supply, the purpose of which is to achieve natural bidirectional flow of energy and zero-voltage turn-on of all switching tubes.

[0006] In order to achieve the above object, the present invention provides a control method for a single-stage architecture divided-capacity power supply, the single-stage architecture divided-capacity power supply comprising:

[0007] High-voltage side switch network, leakage inductance, DC blocking capacitor, high-frequency isolation transformer, current doubler rectifier switch network;

[0008] The input end of the high-voltage side switch network is connected to the high-voltage DC bus, the first output end of the high-voltage side switch network is connected to the first end of the leakage inductor, and the second output end of the high-voltage side switch network is connected to the negative electrode of the DC blocking capacitor;

[0009] The second end of the leakage inductor and the second end of the DC blocking capacitor are both connected to the primary winding of the high-frequency isolation transformer;

[0010] The input end of the current-doubling rectifier switch network is connected to the secondary winding of the high-frequency isolation transformer, and the output end of the current-doubling rectifier switch network is connected to the battery cell;

[0011] Control methods include:

[0012] Step 1: Obtain the voltage reference value of the battery cell, the voltage value of the battery cell, the high-voltage DC bus voltage, and the charge and discharge current value of the single-stage architecture divided capacity power supply;

[0013] Step 2: Compare the voltage reference value of the battery cell with the voltage value of the battery cell and input the result into the first controller for calculation to obtain the current reference value of the battery cell;

[0014] Step 3: Compare the current reference value of the battery cell with the charge and discharge current value of the single-stage architecture divided capacity power supply, and then input the current reference value into the second controller for calculation to obtain the duty cycle;

[0015] Step 4: Inputting the voltage value of the battery cell, the high-voltage DC bus voltage, the charge and discharge current value of the single-stage architecture divided-capacity power supply, and the duty cycle into the third controller for calculation to obtain the first additional mode duration and the second additional mode duration;

[0016] Step 5: Based on the first additional mode duration, the second additional mode duration and the duty cycle, control the PWM signal generating unit to generate a first drive signal for phase-shifting the high-voltage side switch network, and control the PWM signal generating unit to generate a second drive signal for PWM control of the current-doubler rectifier switch network.

[0017] Specifically, the high-side switching network includes:

[0018] a first switching tube, a second switching tube, a third switching tube, a fourth switching tube, a first half-bridge capacitor and a second half-bridge capacitor;

[0019] The drain of the first switching tube is connected to the first end of the first half-bridge capacitor and the positive end of the high-voltage DC bus respectively, and the source of the first switching tube is connected to the drain of the second switching tube to form a first bridge arm. The midpoint of the first bridge arm is connected to the first end of the leakage inductor;

[0020] The source of the second switch tube is respectively connected to the drain of the third switch tube, the second end of the first half-bridge capacitor, and the first end of the second half-bridge capacitor;

[0021] The source of the third switch tube is connected to the drain of the fourth switch tube to form a second bridge arm, and the midpoint of the second bridge arm is connected to the first end of the DC blocking capacitor;

[0022] The source of the fourth switch tube is connected to the second end of the second half-bridge capacitor and the negative end of the high-voltage DC bus respectively;

[0023] The gate of the first switching tube, the gate of the second switching tube, the gate of the third switching tube, and the gate of the fourth switching tube are all connected to the output end of the PWM signal generating unit.

[0024] More specifically, the current-doubling rectifier switching network includes:

[0025] A first power tube, a second power tube, a third power tube, a fourth power tube, a first DC inductor, a second DC inductor, a clamping capacitor, and a port capacitor;

[0026] The source of the first power tube is respectively connected to the first end of the secondary winding of the high-frequency isolation transformer, the drain of the second power tube, and the first end of the first DC inductor; the drain of the first power tube is respectively connected to the drain of the third power tube and the first end of the clamping capacitor;

[0027] The source electrode of the second power tube is respectively connected to the source electrode of the fourth power tube, the second end of the clamping capacitor, the second end of the port capacitor, and the negative end of the battery cell;

[0028] The source of the third power tube is respectively connected to the drain of the fourth power tube, the second end of the secondary winding of the high-frequency isolation transformer, and the first end of the second DC inductor;

[0029] The second end of the second DC inductor is connected to the second end of the first DC inductor, the first end of the port capacitor, and the positive terminal of the battery cell respectively;

[0030] The gate of the first power tube, the gate of the second power tube, the gate of the third power tube, and the gate of the fourth power tube are all connected to the output end of the PWM signal generating unit.

[0031] Furthermore, the driving signals of the first switching tube and the second switching tube are complementary;

[0032] The driving signals of the third switching tube and the fourth switching tube are complementary;

[0033] The driving signals of the first power tube and the second power tube are complementary;

[0034] The driving signals of the third power tube and the fourth power tube are complementary;

[0035] The duty cycles of the driving signals of the first switching tube, the second switching tube, the third switching tube, and the fourth switching tube are all 50%.

[0036] Furthermore, when the single-stage structured capacity-divided power supply is in battery charging condition,

[0037] Introducing a first additional operating mode causes the first switch tube to be turned on earlier than the first power tube by a duration of the first additional mode, or causes the second switch tube to be turned on earlier than the third power tube by a duration of the first additional mode;

[0038] The second additional working mode is introduced to enable the third switch tube to be turned on earlier than the second power tube by the second additional mode duration, or to enable the fourth switch tube to be turned on earlier than the fourth power tube by the second additional mode duration.

[0039] Furthermore, in the battery charging condition, the calculation expressions for the first additional mode duration and the second additional mode duration are respectively:

[0040]

[0041] Among them, L k Leakage inductance, L dc Indicates the DC inductance value, D indicates the duty cycle, T s represents the switching cycle, n represents the transformer ratio, V2 represents the voltage value of the battery cell, i o Indicates the charge and discharge current, and V1 indicates the high-voltage DC bus voltage.

[0042] Furthermore, when the single-stage structured capacity-divided power supply is in battery discharge condition,

[0043] Introducing a third additional working mode causes the first switch tube to be turned on later than the first power tube by a duration of the first additional mode, or causes the second switch tube to be turned on later than the third power tube by a duration of the first additional mode;

[0044] The fourth additional working mode is introduced to enable the third switch tube to be turned on later than the second power tube by the second additional mode duration, or to enable the fourth switch tube to be turned on later than the fourth power tube by the second additional mode duration.

[0045] Furthermore, under the battery discharge condition, the calculation expressions for the first additional mode duration and the second additional mode duration are:

[0046]

[0047] Among them, L k Leakage inductance, L dc Indicates the DC inductance value, D indicates the duty cycle, T s represents the switching cycle, n represents the transformer ratio, V2 represents the voltage value of the battery cell, i o Indicates the charge and discharge current, and V1 indicates the high-voltage DC bus voltage.

[0048] Furthermore, the first switch tube, the second switch tube, the third switch tube, the fourth switch tube, the first power tube, the second power tube, the third power tube, and the fourth power tube are all MOSFET switch tubes with anti-parallel diodes and drain-source parasitic junction capacitances.

[0049] The above solution of the present invention has the following beneficial effects:

[0050] The present invention obtains a voltage reference value of a battery cell, a voltage value of the battery cell, a high-voltage DC bus voltage, and a charge and discharge current value of a single-stage architecture divided-capacity power supply; compares the voltage reference value of the battery cell with the voltage value of the battery cell, and then inputs the comparison result into a first controller for calculation to obtain a current reference value of the battery cell; compares the current reference value of the battery cell with the charge and discharge current value of the single-stage architecture divided-capacity power supply, and then inputs the comparison result into a second controller for calculation to obtain a duty cycle; inputs the voltage reference value of the battery cell, the voltage value of the battery cell, the high-voltage DC bus voltage, the charge and discharge current value of the single-stage architecture divided-capacity power supply, and the duty cycle into a third controller for calculation to obtain a first additional mode duration and a second additional mode duration; and controls a PWM signal generating unit based on the first additional mode duration, the second additional mode duration, and the duty cycle. A first drive signal is generated for performing phase-shift control on the high-voltage side switch network, and the PWM signal generating unit is adjusted to generate a second drive signal for performing PWM control on the current-doubler rectifier switch network. Compared with the prior art, the control method provided by the present invention has the characteristics of positive and negative drive logic consistency, can realize natural bidirectional flow of power, and does not require shutdown operations to change the battery charge and discharge state, thereby meeting the performance index requirements of transient regulation. While performing phase-shift control on the high-voltage side switch network based on the first additional mode duration, the second additional mode duration and the duty cycle, the voltage gain of the divided-capacity power supply is changed by performing PWM control on the current-doubler rectifier switch network, thereby achieving zero-voltage turn-on of all switch tubes while reducing switching losses and EMI noise.

[0051] Other beneficial effects of the present invention will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 A schematic diagram of a flow chart of an embodiment of the present invention;

[0053] Figure 2 This is a schematic diagram of control logic in an embodiment of the present invention;

[0054] Figure 3 The topological structure diagram of the single-stage architecture capacity-divided power supply;

[0055] Figure 4 This is the working waveform diagram of the single-stage architecture divided-capacity power supply under battery charging conditions;

[0056] Figure 5 This is the working equivalent circuit modal diagram of the single-stage architecture divided-capacity power supply in the first half cycle of the battery charging condition;

[0057] Figure 6 The waveform diagram of the drive signal, neutral point voltage, and leakage inductance current of a single-stage structured split-capacity power supply during battery charging.

[0058] Figure 7 This is the working waveform diagram of the single-stage architecture divided-capacity power supply under battery discharge conditions;

[0059] Figure 8 This is the working equivalent circuit modal diagram of the single-stage architecture divided-capacity power supply in the first half cycle under battery discharge conditions;

[0060] Figure 9 The waveforms of the drive signal, neutral point voltage, and leakage inductance current of a single-stage split-capacity power supply during battery discharge. DETAILED DESCRIPTION

[0061] To make the technical problems, technical solutions, and advantages to be solved by the present invention more clear, the following is a detailed description with reference to the accompanying drawings and specific embodiments. It is obvious that the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0062] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0063] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood broadly. For example, they may refer to a locking connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0064] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0065] In view of the existing problems, the present invention provides a control method for a single-stage architecture capacity-divided power supply.

[0066] like Figure 1 and Figure 2 As shown, an embodiment of the present invention provides a control method for a single-stage architecture capacity-divided power supply, the control method comprising:

[0067] Step 1: Obtain the voltage reference value of the battery cell, the voltage value of the battery cell, the high-voltage DC bus voltage, and the charge and discharge current value of the single-stage architecture divided capacity power supply;

[0068] Step 2: Compare the voltage reference value of the battery cell with the voltage value of the battery cell and input the result into the first controller for calculation to obtain the current reference value of the battery cell;

[0069] Step 3: Compare the current reference value of the battery cell with the charge and discharge current value of the single-stage architecture divided capacity power supply, and then input the current reference value into the second controller for calculation to obtain the duty cycle;

[0070] Step 4: Inputting the voltage reference value of the battery cell, the voltage value of the battery cell, the high-voltage DC bus voltage, the charge and discharge current value of the single-stage architecture divided-capacity power supply, and the duty cycle into the third controller for calculation to obtain the first additional modal duration and the second additional modal duration;

[0071] Step 5: Based on the first additional mode duration, the second additional mode duration and the duty cycle, the PWM signal generating unit is controlled to generate a first drive signal for performing phase shift control on the high-voltage side switch network, and the PWM signal generating unit is controlled to generate a second drive signal for performing PWM control on the current doubler rectifier switch network.

[0072] like Figure 3 As shown in the figure, the single-stage architecture divided capacity power supply includes:

[0073] High-side switch network, leakage inductance L k , DC blocking capacitor C b , high-frequency isolation transformer, current-doubler rectifier switch network;

[0074] The input end of the high-voltage side switch network is connected to the high-voltage DC bus, and the first output end of the high-voltage side switch network is connected to the leakage inductance L k The first end of the high-voltage side switch network is connected to the DC blocking capacitor C b Negative connection;

[0075] Leakage inductance L k The second end of the DC blocking capacitor C b The second ends of the high-frequency isolation transformers are connected to the primary windings.

[0076] The input end of the current-doubling rectifier switch network is connected to the secondary winding of the high-frequency isolation transformer, and the output end of the current-doubling rectifier switch network is connected to the battery cell.

[0077] Compared with the traditional two-stage structured capacity-divided power supply, the single-stage structured capacity-divided power supply provided by the embodiment of the present invention has fewer components, lower cost and higher power density.

[0078] Most preferably, the high-side switching network comprises:

[0079] The first switch tube S1, the second switch tube S2, the third switch tube S3, the fourth switch tube S4, the first half-bridge capacitor C d1 and the second half-bridge capacitor C d2 ;

[0080] The drain of the first switch tube S1 is connected to the first half-bridge capacitor C d1 The first end of the first bridge arm is connected to the positive end of the high-voltage DC bus, the source of the first switch tube S1 is connected to the drain of the second switch tube S2, and the first bridge arm is formed. The midpoint A of the first bridge arm is connected to the leakage inductance L k The first end of the connection;

[0081] The source of the second switch tube S2 is connected to the drain of the third switch tube S3 and the first half-bridge capacitor C d1 The second end of the second half-bridge capacitor C d2 The first end of the connection;

[0082] The source of the third switch tube S3 is connected to the drain of the fourth switch tube S4 to form a second bridge arm. The midpoint B of the second bridge arm is connected to the DC blocking capacitor C. b The first end of the connection;

[0083] The source of the fourth switch tube S4 is connected to the second half-bridge capacitor C d2 The second end of the high voltage DC bus is connected to the negative end of the high voltage DC bus;

[0084] The gate of the first switch tube S1 , the gate of the second switch tube S2 , the gate of the third switch tube S3 , and the gate of the fourth switch tube S4 are all connected to the output end of the PWM signal generating unit.

[0085] In the embodiment of the present invention, the first switch tube S1 , the second switch tube S2 , the third switch tube S3 , and the fourth switch tube S4 in the high-voltage side switch network adopt a stacked half-bridge junction structure, which reduces the voltage stress of the switching devices.

[0086] Most preferably, the current-doubling rectifier switching network comprises:

[0087] A first power tube Q1, a second power tube Q2, a third power tube Q3, a fourth power tube Q4, a first DC inductor L1, a second DC inductor L2, a clamping capacitor C3, and a port capacitor C2;

[0088] The source of the first power tube Q1 is respectively connected to the first end of the secondary winding of the high-frequency isolation transformer, the drain of the second power tube Q2, and the first end of the first DC inductor L1; the drain of the first power tube Q1 is respectively connected to the drain of the third power tube Q3 and the first end of the clamping capacitor C3;

[0089] The source of the second power tube Q2 is connected to the source of the fourth power tube Q4, the second end of the clamping capacitor C3, the second end of the port capacitor C2, and the negative end of the battery cell respectively;

[0090] The source of the third power tube Q3 is connected to the drain of the fourth power tube Q4, the second end of the secondary winding of the high-frequency isolation transformer, and the first end of the second DC inductor L2 respectively;

[0091] The second end of the second DC inductor L2 is respectively connected to the second end of the first DC inductor L1, the first end of the port capacitor C2, and the positive terminal of the battery cell;

[0092] The gate of the first power tube Q1 , the gate of the second power tube Q2 , the gate of the third power tube Q3 , and the gate of the fourth power tube Q4 are all connected to the output end of the PWM signal generating unit.

[0093] In an embodiment of the present invention, the source of the first power tube Q1 in the current doubler rectifier switch network is connected to the drain of the second power tube Q2 to form a third bridge arm, the midpoint of which is C, the source of the third power tube Q3 is connected to the drain of the fourth power tube Q4 to form a fourth bridge arm, the midpoint of which is D, and the inductance of the first DC inductor L1 and the second DC inductor L2 are the same.

[0094] In an embodiment of the present invention, the current-doubling rectifier switch network adopts a current-doubling rectifier structure, which reduces the current stress of the device and solves the voltage spike problem of the second power tube Q2 and the fourth power tube Q4 when the battery is discharged through an active clamping circuit composed of the first power tube Q1, the third power tube Q3 and the clamping capacitor C3.

[0095] In the embodiment of the present invention, the high-voltage DC bus voltage V1 ranges from 700 to 800 V, the rated operating voltage is 750 V, the battery cell voltage V2 ranges from 0 to 5 V, and the current ranges from -200 A to 200 A.

[0096] Most preferably, the first switch tube S1, the second switch tube S2, the third switch tube S3, the fourth switch tube S4, the first power tube Q1, the second power tube Q2, the third power tube Q3, and the fourth power tube Q4 are all MOSFET switch tubes with anti-parallel diodes and drain-source parasitic junction capacitances.

[0097] The signal meanings defined in the embodiments of the present invention include:

[0098] The high-voltage DC bus voltage is V1, the cell voltage is V2, and the current flowing through the leakage inductance L k The leakage current is i p , the secondary current is i s , the current flowing through the first DC inductor L1 is i1, the current flowing through the second DC inductor L2 is i2, and the charging and discharging current is i o, the voltage of the primary neutral point is v AB , the voltage of the secondary neutral point is v CD .

[0099] Specifically, the driving signals of the first switch tube S1 and the second switch tube S2 are complementary;

[0100] The driving signals of the third switch tube S3 and the fourth switch tube S4 are complementary;

[0101] The driving signals of the first power tube Q1 and the second power tube Q2 are complementary;

[0102] The driving signals of the third power tube Q3 and the fourth power tube Q4 are complementary;

[0103] The duty cycles of the driving signals of the first switch tube S1 , the second switch tube S2 , the third switch tube S3 , and the fourth switch tube S4 are all 50%.

[0104] In an embodiment of the present invention, the first controller and the second controller are both PI controllers, and the third controller is a DSP controller, which is used to control the PWM signal generating unit to generate complementary drive signals. The drive signals are isolated and power amplified to provide drive signals for the switching tubes and the power tubes. The drive signals include a first drive signal and a second drive signal. The first drive signal is used to drive the first to fourth switching tubes S4, and the second drive signal is used to drive the first to fourth power tubes Q4. In the first drive signal, the drive signal used to drive the first switching tube S1 is complementary to the drive signal used to drive the second switching tube S2, and the drive signal used to drive the third switching tube S3 is complementary to the drive signal used to drive the fourth switching tube S4. In the second drive signal, the drive signal used to drive the first power tube Q1 is complementary to the drive signal used to drive the second power tube Q2, and the drive signal used to drive the third power tube Q3 is complementary to the drive signal used to drive the fourth power tube Q4.

[0105] In an embodiment of the present invention, the single-stage architecture divided-capacity power supply includes forward energy transmission and reverse energy transmission modes. In the forward energy transmission mode, when the cell voltage is lower than the voltage set by the single-stage architecture divided-capacity power supply, energy flows forward, so that the battery is in a charging state, and therefore it can be defined as a battery charging condition. In the reverse energy transmission mode, when the cell voltage is higher than the voltage set by the single-stage architecture divided-capacity power supply, energy flows in the reverse direction, and the battery is in a discharging state, and therefore it can be defined as a battery discharging condition.

[0106] Specifically, when the single-stage structure divided capacity power supply is in battery charging condition,

[0107] The first additional working mode is introduced to make the first switch tube S1 lead the first power tube Q1 by the first additional mode duration t d1 Turn on, or make the second switch S2 lead the third power tube Q3 by the first additional mode duration t d1Open;

[0108] The introduction of the second additional working mode makes the third switch tube S3 lead the second power tube Q2 by the duration of the second additional mode t d2 Turn on, or make the fourth switch tube S4 lead the fourth power tube Q4 by the second additional mode duration t d2 Activated.

[0109] In the embodiment of the present invention, the first additional working mode is that the first switch tube S1, the fourth switch tube S4, the second power tube Q2, and the fourth power tube Q4 are in the on state, or the second switch tube S2, the third switch tube S3, the second power tube Q2, and the fourth power tube Q4 are in the on state;

[0110] The second additional working mode is that the first switch tube S1, the third switch tube S3, the first power tube Q1, and the fourth power tube Q4 are in the on state, or the second switch tube S2, the fourth switch tube S4, the second power tube Q2, and the third power tube Q3 are in the on state.

[0111] Specifically, in the battery charging condition, the calculation expressions for the first additional mode duration and the second additional mode duration are:

[0112]

[0113] Among them, L k Leakage inductance, L dc Indicates the DC inductance value, D indicates the duty cycle, T s represents the switching cycle, n represents the transformer ratio, V2 represents the voltage value of the battery cell, i o Indicates the charge and discharge current, and V1 indicates the high-voltage DC bus voltage.

[0114] Specifically, when the battery is charging, the working waveform of the single-stage architecture split-capacity power supply is as follows: Figure 4 As shown, the equivalent circuit mode is as follows Figure 5 As shown, the working process is as follows:

[0115] At time t0, the second switch tube S2 is turned off, and the fourth switch tube S4, the second power tube Q2, and the fourth power tube Q4 remain turned on; at this time, the leakage inductance current i p The parasitic junction capacitance of the second switch tube S2 and the first switch tube S1 are charged and discharged respectively. If the parameter design is reasonable, the parasitic junction capacitance of the first switch tube S1 can be discharged within the dead time of t0~t1, laying the foundation for the zero voltage turn-on of the first switch tube S1, and the primary neutral point voltage v AB From V1 / 2 to V1;

[0116] At time t1, the first switch tube S1 is turned on at zero voltage, and the fourth switch tube S4, the second power tube Q2, and the fourth power tube Q4 remain turned on. During the additional working mode t1 to t2, the primary neutral point voltage v AB is V1, the secondary neutral point voltage v CD is 0, which means that the leakage inductance L k There is a potential difference between the two ends, and the leakage current i p The current polarity changes from negative to positive until the leakage current i p The current i1 is greater than the current of the first DC inductor L1, that is, the zero voltage turn-on condition of the first power tube Q1 is met;

[0117] At time t2, the second power tube Q2 is turned off, and the first switch tube S1, the fourth switch tube S4, and the fourth power tube Q4 remain turned on. At this time, the transformer current i s The current i1 is greater than the current of the first DC inductor L1, which meets the zero voltage turn-on condition of the first power tube Q1. The secondary side center point voltage v CD Transformed into V C3 ;

[0118] At time t3, the first power tube Q1 is turned on at zero voltage, and the first switch tube S1, the fourth switch tube S4, and the fourth power tube Q4 remain in the on state. At this time, the voltage on both sides of the transformer is established, and energy begins to be transferred from the primary side to the secondary side.

[0119] At time t4, the fourth switch tube S4 is turned off, and the first switch tube S1, the first power tube Q1, and the fourth power tube Q4 remain turned on. At this time, the leakage inductance current i p The polarity is positive, and the energy stored in the parasitic junction capacitance of the third switch tube S3 is released. If the parameters are properly designed, the parasitic junction capacitance of the third switch tube S3 can be completely discharged within the dead time of t4 to t5, that is, the zero voltage turn-on of the third switch tube S3 can be achieved;

[0120] At time t5, the third switch tube S3 is turned on at zero voltage, and the first switch tube S1, the first power tube Q1, and the fourth power tube Q4 remain turned on. During the additional working mode t5 to t6, the leakage inductance current i p Under the action of potential difference, it begins to decrease to reduce reactive current. In order to ensure the leakage inductance L k It has enough energy to realize the zero voltage turn-on of the second switch tube S2, and the duration of the second additional mode is t d2 Requires reasonable design;

[0121] At time t6, the first power tube Q1 is turned off, the first switch tube S1, the third switch tube S3, and the fourth power tube Q4 remain on, and the converted current i1 of the first DC inductor L1 is much larger than the leakage inductance current i p, so the second power tube Q2 has the condition of zero voltage turn-on;

[0122] At time t7, the second power tube Q2 is turned on at zero voltage, and the first switch tube S1, the third switch tube S3, and the fourth power tube Q4 remain turned on;

[0123] T7 to T8 belongs to the reactive transmission stage. During this stage, the voltage on both sides of the transformer is not established, so there is no energy interaction;

[0124] Due to the periodic symmetry of the control strategy, the working principle of the second half cycle is similar to that of the first half cycle. Therefore, the embodiment of the present invention will not further describe the working principle of the second half cycle.

[0125] like Figure 6 As shown in the figure, it shows that when the battery is charging, the single-stage architecture divided capacity power supply provided by the embodiment of the present invention works at V1=750V, V2=5V, i o = Each switch tube driving waveform under 200A working condition, neutral point voltage v AB With v CD Waveform, and leakage current i p waveform.

[0126] Specifically, when the single-stage structure divided capacity power supply is in battery discharge condition,

[0127] The third additional working mode is introduced to make the first switch tube S1 lag behind the first power tube Q1 by the duration of the first additional mode t d1 Turn on, or make the second switch S2 lag behind the third power tube Q3 by the first additional mode duration t d1 Open;

[0128] The fourth additional working mode is introduced to make the third switch tube S3 lag behind the second power tube Q2 by the second additional mode duration t d2 Turn on, or make the fourth switch tube S4 lag behind the fourth power tube Q4 by the second additional mode duration t d2 Activated.

[0129] In the embodiment of the present invention, the third additional working mode is that the second switch tube S2, the fourth switch tube S4, the first power tube Q1, and the fourth power tube Q4 are in the on state, or the first switch tube S1, the third switch tube S3, the second power tube Q2, and the third power tube Q3 are in the on state;

[0130] The fourth additional working mode is that the first switch tube S1, the fourth switch tube S4, the second power tube Q2, and the fourth power tube Q4 are in the on state, or the second switch tube S2, the third switch tube S3, the second power tube Q2, and the fourth power tube Q4 are in the on state.

[0131] Specifically, under the battery discharge condition, the calculation expressions for the first additional mode duration and the second additional mode duration are:

[0132]

[0133] Among them, L k Leakage inductance, L dc Indicates the DC inductance value, D indicates the duty cycle, T s represents the switching cycle, n represents the transformer ratio, V2 represents the voltage value of the battery cell, i o Indicates the charge and discharge current, and V1 indicates the high-voltage DC bus voltage.

[0134] Specifically, when the battery is discharging, the operating waveform of the single-stage architecture split-capacity power supply is as follows: Figure 7 As shown, the equivalent circuit mode is as follows Figure 8 As shown, the working process is as follows:

[0135] At time t0, the second power tube Q2 is turned off, and the second switch tube S2, the fourth switch tube S4, and the fourth power tube Q4 remain turned on. At this time, the transformer current i s The current i1 being greater than the current of the first DC inductor L1 means that the current polarity of the difference between the two currents is consistent with the conduction direction of the body diode of the first power transistor Q1. Therefore, the first power transistor Q1 meets the theoretical conditions for achieving zero voltage.

[0136] At time t1, the first power tube Q1 achieves zero voltage turn-on, the second switch tube S2, the fourth switch tube S4, and the fourth power tube Q4 remain turned on, t1 to t2 is the third additional working mode, and the duration is the first additional mode duration t d1 , in this stage, the primary neutral point v AB The voltage is V1 / 2, the secondary neutral point v CD The voltage is V C3 , leakage inductance L k There is a potential difference between the two ends, so the leakage current begins to decrease;

[0137] At time t2, the second switch tube S2 is turned off, and the fourth switch tube S4, the first power tube Q1, and the fourth power tube Q4 remain turned on. At this time, the leakage inductance current i p The polarity is negative, which can discharge the parasitic junction capacitance in the first switch tube S1 and charge the parasitic junction capacitance in the second switch tube S2. If the parameters are properly designed, the parasitic junction capacitance in the first switch tube S1 can be completely discharged within the dead time of t2 to t3.

[0138] At time t3, the first switch tube S1 is turned on at zero voltage, and the fourth switch tube S4, the first power tube Q1, and the fourth power tube Q4 remain in the on state. At this time, the voltage on both sides of the transformer is established, and energy is transferred from the primary side to the secondary side.

[0139] At time t4, the first power tube Q1 is turned off, and the first switch tube S1, the fourth switch tube S4, and the fourth power tube Q4 remain turned on. At this time, the converted current i1 of the first DC inductor L1 is much larger than the leakage inductance current i p , which means that the energy stored in the parasitic junction capacitance of the second power tube Q2 can be completely released, that is, the second power tube Q2 has the basic conditions for zero voltage turn-on;

[0140] At t5, the second power tube Q2 is turned on at zero voltage, and the first switch tube S1, the fourth switch tube S4, and the fourth power tube Q4 remain turned on. t5 to t6 are the fourth additional working mode. During this stage, the primary neutral point voltage v AB The voltage is V1, the secondary neutral point v CD The voltage is 0, the leakage current i p Under the action of potential difference, it begins to decrease, and the duration of the second additional mode in this stage is reasonably designed. d2 Ensure the zero voltage condition of the third switch tube S3;

[0141] At time t6, the fourth switch S4 is turned off, while the first switch S1, the second power transistor Q2, and the fourth power transistor Q4 remain on. At this time, the leakage current polarity is negative, which is consistent with the natural conduction direction of the body diode of the third switch S3. This means that the third switch S3 meets the basic conditions for zero-voltage turn-on.

[0142] At time t7, the third switch tube S3 is turned on at zero voltage, and the first switch tube S1, the second power tube Q2, and the fourth power tube Q4 remain turned on;

[0143] T7 to T8 belongs to the reactive phase. During this phase, the voltage on both sides of the transformer is not established, so there is no energy interaction;

[0144] Due to the periodic symmetry of the control strategy, the working principle of the second half cycle is similar to that of the first half cycle, and the embodiment of the present invention will not further describe the working process of the second half cycle.

[0145] Figure 9 It shows that when the battery is discharged, the single-stage architecture capacity-divided power supply provided by the embodiment of the present invention works at V1=750V, V2=5V, i o = Each switch tube driving waveform and neutral point voltage v under -200A working condition AB With v CD Waveform, and leakage current i p waveform.

[0146] The embodiment of the present invention obtains the voltage reference value of the battery cell, the voltage value of the battery cell, the high-voltage DC bus voltage, and the charge and discharge current value of the single-stage architecture divided-capacity power supply; the voltage reference value of the battery cell is compared with the voltage value of the battery cell and then input into the first controller for calculation to obtain the current reference value of the battery cell; the current reference value of the battery cell is compared with the charge and discharge current value of the single-stage architecture divided-capacity power supply and then input into the second controller for calculation to obtain the duty cycle; the voltage value of the battery cell, the high-voltage DC bus voltage, the charge and discharge current value of the single-stage architecture divided-capacity power supply, and the duty cycle are input into the third controller for calculation to obtain the first additional mode duration and the second additional mode duration; based on the first additional mode duration, the second additional mode duration and the duty cycle, the PWM signal generating unit is controlled to generate A first drive signal is generated for phase-shifting the high-voltage side switch network, and a PWM signal generating unit is controlled to generate a second drive signal for PWM control of the current-doubling rectifier switch network. Compared with the prior art, the control method provided in the embodiment of the present invention has the characteristics of positive and negative drive logic consistency, can realize natural bidirectional flow of power, and does not require shutdown operations to change the battery charge and discharge status, thereby meeting the performance index requirements of transient regulation. While the high-voltage side switch network is phase-shifted based on the first additional mode duration, the second additional mode duration and the duty cycle, the voltage gain is changed by PWM control of the current-doubling rectifier switch network, thereby achieving zero-voltage turn-on of all switch tubes while reducing switching losses and reducing EMI noise.

[0147] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A control method for a single-stage structured capacity-divided power supply, characterized in that: The single-stage architecture divided capacity power supply includes: High-voltage side switch network, leakage inductance, DC blocking capacitor, high-frequency isolation transformer, current doubler rectifier switch network; The input end of the high-voltage side switch network is connected to the high-voltage DC bus, the first output end of the high-voltage side switch network is connected to the first end of the leakage inductor, and the second output end of the high-voltage side switch network is connected to the negative electrode of the DC blocking capacitor; The second end of the leakage inductor and the second end of the DC blocking capacitor are both connected to the primary winding of the high-frequency isolation transformer; The input end of the current-doubling rectifier switch network is connected to the secondary winding of the high-frequency isolation transformer, and the output end of the current-doubling rectifier switch network is connected to the battery cell; The control method includes: Step 1: Obtain the voltage reference value of the battery cell, the voltage value of the battery cell, the high-voltage DC bus voltage, and the charge and discharge current value of the single-stage architecture divided-capacity power supply; Step 2, comparing the voltage reference value of the battery cell with the voltage value of the battery cell and inputting the comparison results into a first controller for calculation to obtain a current reference value of the battery cell; Step 3, comparing the current reference value of the battery cell with the charge and discharge current value of the single-stage architecture divided capacity power supply, and then inputting the result into a second controller for calculation to obtain a duty cycle; Step 4: Inputting the voltage value of the battery cell, the high-voltage DC bus voltage, the charge and discharge current value of the single-stage architecture divided-capacity power supply, and the duty cycle into a third controller for calculation to obtain a first additional modal duration and a second additional modal duration; Step 5: Based on the first additional mode duration, the second additional mode duration and the duty cycle, control the PWM signal generating unit to generate a first drive signal for performing phase-shift control on the high-side switching network, and control the PWM signal generating unit to generate a second drive signal for performing PWM control on the current-doubler rectifier switching network.

2. The control method of the single-stage architecture capacity-divided power supply according to claim 1, characterized in that: The high-voltage side switch network includes: a first switching tube, a second switching tube, a third switching tube, a fourth switching tube, a first half-bridge capacitor and a second half-bridge capacitor; The drain of the first switching tube is respectively connected to the first end of the first half-bridge capacitor and the positive end of the high-voltage DC bus, and the source of the first switching tube is connected to the drain of the second switching tube to form a first bridge arm, and the midpoint of the first bridge arm is connected to the first end of the leakage inductor; The source of the second switch tube is respectively connected to the drain of the third switch tube, the second end of the first half-bridge capacitor, and the first end of the second half-bridge capacitor; The source of the third switching tube is connected to the drain of the fourth switching tube to form a second bridge arm, and the midpoint of the second bridge arm is connected to the first end of the DC blocking capacitor; The source of the fourth switch tube is connected to the second end of the second half-bridge capacitor and the negative end of the high-voltage DC bus respectively; The gate of the first switching tube, the gate of the second switching tube, the gate of the third switching tube, and the gate of the fourth switching tube are all connected to the output end of the PWM signal generating unit.

3. The control method of the single-stage architecture capacity-divided power supply according to claim 2, characterized in that: The current-doubling rectifier switch network includes: A first power tube, a second power tube, a third power tube, a fourth power tube, a first DC inductor, a second DC inductor, a clamping capacitor, and a port capacitor; The source of the first power tube is respectively connected to the first end of the secondary winding of the high-frequency isolation transformer, the drain of the second power tube, and the first end of the first DC inductor; the drain of the first power tube is respectively connected to the drain of the third power tube and the first end of the clamping capacitor; The source electrode of the second power tube is respectively connected to the source electrode of the fourth power tube, the second end of the clamping capacitor, the second end of the port capacitor, and the negative end of the battery cell; The source of the third power tube is respectively connected to the drain of the fourth power tube, the second end of the secondary winding of the high-frequency isolation transformer, and the first end of the second DC inductor; The second end of the second DC inductor is connected to the second end of the first DC inductor, the first end of the port capacitor, and the positive terminal of the battery cell respectively; The gate of the first power tube, the gate of the second power tube, the gate of the third power tube, and the gate of the fourth power tube are all connected to the output end of the PWM signal generating unit.

4. The control method of the single-stage architecture capacity-divided power supply according to claim 3, characterized in that: The driving signals of the first switching tube and the second switching tube are complementary; The driving signals of the third switching tube and the fourth switching tube are complementary; The driving signals of the first power tube and the second power tube are complementary; The driving signals of the third power tube and the fourth power tube are complementary; The duty cycles of the driving signals of the first switching tube, the second switching tube, the third switching tube, and the fourth switching tube are all 50%.

5. The control method of the single-stage architecture capacity-divided power supply according to claim 4, characterized in that: The single-stage architecture capacity-divided power supply is in battery charging condition. Introducing a first additional operating mode causes the first switch tube to be turned on earlier than the first power tube by a first additional mode duration, or causes the second switch tube to be turned on earlier than the third power tube by a first additional mode duration; The second additional working mode is introduced to enable the third switch tube to be turned on earlier than the second power tube by the second additional mode duration, or the fourth switch tube to be turned on earlier than the fourth power tube by the second additional mode duration.

6. The control method of the single-stage architecture capacity-divided power supply according to claim 5, characterized in that: In the battery charging condition, the calculation expressions of the first additional mode duration and the second additional mode duration are respectively: Among them, L k Leakage inductance, L dc Indicates the DC inductance value, D indicates the duty cycle, T s represents the switching cycle, n represents the transformer ratio, V2 represents the voltage value of the battery cell, i o Indicates the charge and discharge current, and V1 indicates the high-voltage DC bus voltage.

7. The control method of the single-stage architecture capacity-divided power supply according to claim 4, characterized in that: The single-stage architecture capacity-divided power supply is in battery discharge condition. Introducing a third additional working mode causes the first switch tube to be turned on later than the first power tube by a first additional mode duration, or causes the second switch tube to be turned on later than the third power tube by a first additional mode duration; The fourth additional working mode is introduced to enable the third switch tube to be turned on later than the second power tube by a second additional mode duration, or to enable the fourth switch tube to be turned on later than the fourth power tube by a second additional mode duration.

8. The control method of the single-stage architecture capacity-divided power supply according to claim 7, characterized in that: In the battery discharging condition, the calculation expressions of the first additional mode duration and the second additional mode duration are respectively: Among them, L k Leakage inductance, L dc Indicates the DC inductance value, D indicates the duty cycle, T s represents the switching cycle, n represents the transformer ratio, V2 represents the voltage value of the battery cell, i o Indicates the charge and discharge current, and V1 indicates the high-voltage DC bus voltage.

9. The control method of the single-stage architecture capacity-divided power supply according to claim 7, characterized in that: The first switch tube, the second switch tube, the third switch tube, the fourth switch tube, the first power tube, the second power tube, the third power tube, and the fourth power tube are all MOSFET switch tubes with anti-parallel diodes and drain-source parasitic junction capacitances.

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