Control method of single-stage architecture capacity grading power supply

Abstract

The invention provides a control method of a single-stage architecture capacity grading power supply, which comprises the following steps of: comparing a voltage reference value of a battery cell with an actual voltage value and then calculating to obtain a current reference value of the battery cell; comparing the current reference value of the battery cell with the charging and discharging current values of the single-stage architecture capacity grading power supply, and then calculating to obtain a duty ratio; first extra modal duration and second extra modal duration are obtained through calculation of the voltage value of the battery cell, the voltage of the high-voltage direct-current bus, the charge and discharge current value of the single-stage architecture capacity grading power supply and the duty ratio; and performing phase shift control on the high-voltage side switching network based on the first extra mode duration, the second extra mode duration and the duty ratio, and performing PWM control on the current-doubling rectification switching network to change the voltage gain of the capacity-grading power supply, thereby realizing natural bidirectional flow of energy and zero-voltage switching of a full switching tube.

Description

Technical Field

[0001] The present invention relates to the technical field of power electronics, 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 led to an increase in the installed capacity of power batteries year by year, which will result in a large number of retired power batteries to be processed every year in the future. The cascade utilization of retired power batteries can not only reduce the pollution to the environment, but also avoid waste of resources and maximize economic benefits; and the important process of the cascade utilization of retired power batteries is capacity separation, that is, by charging and discharging them multiple times to evaluate their remaining battery capacity.

[0003] Most traditional capacity-divided power supply devices adopt 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, which makes it difficult to improve the efficiency and power density of the device.

[0004] Although in recent years, the existing technology has proposed a single-stage architecture divided-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 charging and discharging state is switched, the switch tube driving 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 switching of all switch 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 inductance, 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 doubler rectifier switch network is connected to the secondary winding of the high-frequency isolation transformer, and the output end of the current doubler rectifier switch network is connected to the battery cell;

[0011] Control methods include:

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

[0013] 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 the first controller for calculation to obtain the current reference value of the battery cell;

[0014] 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 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 shift control of 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 switch tube, a second switch tube, a third switch tube, a fourth switch tube, a first half-bridge capacitor and a second half-bridge capacitor;

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

[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 respectively connected to the second end of the second half-bridge capacitor and the negative end of the high-voltage DC bus;

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

[0024] More specifically, the current doubler 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, and 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 respectively 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;

[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 switch tube and the second switch tube are complementary;

[0032] The driving signals of the third switch tube and the fourth switch 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 ratios of the driving signals of the first switch tube, the second switch tube, the third switch tube, and the fourth switch tube are all 50%.

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

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

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

[0040]

[0041] Among them, L k Leakage inductance, L dc represents the DC inductance value, D represents the duty cycle, T s represents the switching cycle, n represents the transformer ratio, V 2 Indicates the voltage value of the battery cell, i o Represents the charge and discharge current, V 1 Indicates the high-voltage DC bus voltage.

[0042] Furthermore, when the battery is discharged, the single-stage structure divided capacity power supply

[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 make the third switch tube turn on later than the second power tube by the second additional mode duration, or to make the fourth switch tube turn on later than the fourth power tube by the second additional mode duration.

[0045] Specifically, under the battery discharge condition, the calculation expressions of the first additional mode duration and the second additional mode duration are respectively:

[0046]

[0047] Among them, L k Leakage inductance, L dc represents the DC inductance value, D represents the duty cycle, T s represents the switching cycle, n represents the transformer ratio, V 2 Indicates the voltage value of the battery cell, i o Represents the charge and discharge current, V 1 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 having anti-parallel diodes and drain-source parasitic junction capacitances.

[0049] The above scheme 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 results 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 results 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 modal duration and a second additional modal duration; based on the first additional modal duration, the second additional modal duration and the duty cycle, controls a PWM signal generating unit A first drive signal is generated for phase-shifting control of the high-voltage side switch network, and a PWM signal generating unit is adjusted to generate a second drive signal for PWM control of 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, and can realize natural bidirectional flow of power without the need to shut down the operation to change the battery charge and discharge state, 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 of the divided-capacity power supply is changed by PWM control of the current-doubler rectifier switch network, so as to realize zero-voltage turning-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 It is a schematic diagram of a flow chart of an embodiment of the present invention;

[0053] Figure 2 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 It is the working waveform diagram of the single-stage architecture capacity-divided power supply under the battery charging condition;

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

[0057] Figure 6 The waveform diagram of the driving signal, neutral point voltage and leakage inductance current of the single-stage structure divided-capacity power supply during battery charging;

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

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

[0060] Fig. 9 The waveform diagram of the driving signal, neutral point voltage and leakage inductance current of the single-stage architecture divided-capacity power supply during battery discharge. DETAILED DESCRIPTION

[0061] In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, the following will be described in detail with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work 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", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0063] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a locking 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, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to 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 structured 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 divided-capacity power supply, the control method comprising:

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

[0068] 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 the first controller for calculation to obtain the current reference value of the battery cell;

[0069] 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 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 mode duration and the second additional mode duration;

[0071] 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 shift control of 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.

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

[0073] High-voltage 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-isolating capacitor C b The negative connection of

[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 of the high-frequency isolation transformers;

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

[0077] Compared with the traditional two-stage structured divided capacity power supply, the single-stage structured divided capacity 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 switch network comprises:

[0079] The first switch tube S 1 , the second switch tube S 2 , the third switch tube S 3 , the fourth switch tube S 4 , the first half bridge capacitor C d1 and the second half-bridge capacitor C d2 ;

[0080] The first switch tube S 1 The drain of the first half bridge capacitor C d1 The first switch tube S 1 The source of the second switch tube S 2 The drain of the first bridge arm is connected to form the first bridge arm. The midpoint A of the first bridge arm is connected to the leakage inductance L k A first end is connected;

[0081] The second switch tube S 2 The source of the third switch tube S 3 The drain of the first half bridge capacitor C d1 The second end of the second half-bridge capacitor C d2 A first end is connected;

[0082] The third switch tube S 3 The source of the fourth switch tube S 4 The drain of the second bridge arm is connected to form the second bridge arm. The midpoint B of the second bridge arm is connected to the DC blocking capacitor C b A first end is connected;

[0083] The fourth switch tube S 4 The source of the second half-bridge capacitor C d2 The second end of the high voltage DC bus is connected to the negative terminal of the high voltage DC bus;

[0084] The first switch tube S 1 The gate of the second switch tube S 2 The gate of the third switch tube S 3 The gate of the fourth switch tube S 4 The gates 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 S in the high-voltage side switch network 1 , the second switch tube S 2 , the third switch tube S 3 , the fourth switch tube S 4 The stacked half-bridge junction structure is adopted to reduce the voltage stress of the switching device.

[0086] Most preferably, the current doubler rectifier switch network comprises:

[0087] The first power tube Q 1 , the second power tube Q 2 、The third power tube Q 3 、The fourth power tube Q 4 , the first DC inductor L 1 , the second DC inductor L 2 , Clamping capacitor C 3 , port capacitance C 2 ;

[0088] The first power tube Q 1 The source of the high-frequency isolation transformer is respectively connected to the first end of the secondary winding and the second power tube Q 2 The drain of the first DC inductor L 1 The first end of the first power tube Q 1 The drain of the third power tube Q 3 The drain and clamping capacitor C 3 A first end is connected;

[0089] The second power tube Q 2 The source of the fourth power tube Q 4 The source and clamping capacitor C 3 The second end, port capacitance C 2 The second end of the battery is connected to the negative terminal of the battery cell;

[0090] The third power tube Q 3 The source of the fourth power tube Q 4 The drain of the high-frequency isolation transformer, the second end of the secondary winding, and the second DC inductor L 2 A first end is connected;

[0091] The second DC inductor L 2 The second end of the first DC inductor L 1 The second end, port capacitance C 2 The first end of the battery is connected to the positive terminal of the battery cell;

[0092] The first power tube Q 1 The gate of the second power tube Q 2 The gate of the third power tube Q 3 The gate of the fourth power tube Q 4 The gates are all connected to the output end of the PWM signal generating unit.

[0093] In the embodiment of the present invention, the first power tube Q in the current doubler rectifier switch network 1 The source of the second power tube Q 2 The drain of the third bridge arm is connected to form the third bridge arm, the midpoint of which is C, and the third power tube Q 3The source of the fourth power tube Q 4 The drain of the first DC inductor L is connected to form a fourth bridge arm, the midpoint of which is D. 1 and the second DC inductor L 2 The sense value is the same.

[0094] In the embodiment of the present invention, the current doubler rectifier switch network adopts a current doubler rectifier structure, which reduces the current stress of the device and 1 、The third power tube Q 3 and clamping capacitor C 3 The active clamp circuit is composed of the second power tube Q 2 、The fourth power tube Q 4 voltage spike problem.

[0095] In the embodiment of the present invention, the high-voltage DC bus voltage V 1 The range is 700~800V, the rated working voltage is 750V, and the voltage V 2 The range is 0~5V, and the current range is -200A~200A.

[0096] Most preferably, the first switch tube S 1 , the second switch tube S 2 , the third switch tube S 3 , the fourth switch tube S 4 , the first power tube Q 1 , the second power tube Q 2 、The third power tube Q 3 、The fourth power tube Q 4 All of them are MOSFET switch tubes with anti-parallel diodes and drain-source parasitic junction capacitance.

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

[0098] The high voltage DC bus voltage is V 1 , the voltage of the cell is V 2 , flows through the leakage inductance L k The leakage current is i p , the secondary current is i s , flows through the first DC inductor L 1 The current is i 1 , flows through the second DC inductor L 2 The current is i 2 , the charge and discharge current is i o , the voltage of the primary neutral point is v AB , the voltage at the secondary neutral point is v CD .

[0099] Specifically, the first switch tube S 1With the second switch tube S 2 The driving signals are complementary;

[0100] The third switch tube S 3 With the fourth switch tube S 4 The driving signals are complementary;

[0101] The first power tube Q 1 With the second power tube Q 2 The driving signals are complementary;

[0102] The third power tube Q 3 With the fourth power tube Q 4 The driving signals are complementary;

[0103] The first switch tube S 1 , the second switch tube S 2 , the third switch tube S 3 , the fourth switch tube S 4 The duty cycle of the driving signal is 50%.

[0104] In the 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 switch tube and the power tube. 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 switch tubes S 4 The second driving signal is used to drive the first to fourth power tubes Q 4 , in the first driving signal, is used to drive the first switch tube S 1 and used to drive the second switch tube S 2 The driving signal is complementary to that of the third switch tube S 3 and for driving the fourth switch tube S 4 The driving signal of the second driving signal is complementary to that of the first power tube Q. 1 And used to drive the second power tube Q 2 The driving signal is complementary to drive the third power tube Q 3 And used to drive the fourth power tube Q 4 The driving signals are complementary.

[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. The forward energy transmission mode means that when the cell voltage is lower than the voltage set by the single-stage architecture divided-capacity power supply, the energy flows forward, so that the battery is in a charging state, and thus it can be defined as a battery charging condition. The reverse energy transmission mode means that when the cell voltage is higher than the voltage set by the single-stage architecture divided-capacity power supply, the energy flows in the reverse direction, and the battery is in a discharging state, and thus it can be defined as a battery discharging condition.

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

[0107] The first additional working mode is introduced to make the first switch tube S 1 Q than the first power tube 1 The duration of the first additional mode ahead is t d1 Turn on, or enable the second switch S 2 Q of the third power tube 3 The duration of the first additional mode ahead is t d1 Open;

[0108] The introduction of the second additional working mode makes the third switch tube S 3 Than the second power tube Q 2 Leading second additional mode duration t d2 Turn on, or enable the fourth switch tube S 4 Q of the fourth power tube 4 Leading second additional mode duration t d2 Open.

[0109] In the embodiment of the present invention, the first additional working mode is that the first switch tube S 1 , the fourth switch tube S 4 , the second power tube Q 2 、The fourth power tube Q 4 In the on state, or the second switch tube S 2 , the third switch tube S 3 , the second power tube Q 2 、The fourth power tube Q 4 In the open state;

[0110] The second additional working mode is that the first switch tube S 1 , the third switch tube S 3 , the first power tube Q 1 、The fourth power tube Q 4 In the on state, or the second switch tube S 2 , the fourth switch tube S 4 , the second power tube Q 2 、The third power tube Q 3 In open state.

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

[0112]

[0113] Among them, L k Leakage inductance, L dcrepresents the DC inductance value, D represents the duty cycle, T s represents the switching cycle, n represents the transformer ratio, V 2 Indicates the voltage value of the battery cell, i o Represents the charge and discharge current, V 1 Indicates the high-voltage DC bus voltage.

[0114] Specifically, when the battery is charging, the operating 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] In t 0 At this moment, the second switch tube S 2 Turn off, the fourth switch tube S 4 , the second power tube Q 2 、The fourth power tube Q 4 Keep it turned on; at this time, the leakage inductance current i p The second switch tube S 2 And the first switch tube S 1 The parasitic junction capacitance is charged and discharged. If the parameters are designed reasonably, it can be 0 ~t 1 The first switch S is completed within the dead time. 1 The discharge of the parasitic junction capacitance in the first switch tube S 1 The zero voltage switch-on lays the foundation, and the primary neutral point voltage v AB By V 1 / 2 becomes V 1 ;

[0116] In t 1 At this moment, the first switch tube S 1 To achieve zero voltage switching, the fourth switch tube S 4 , the second power tube Q 2 、The fourth power tube Q 4 Keep it open, in this additional working mode t 1 ~t 2 During this time, the primary neutral point voltage v AB V 1 , 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 inductance current i p Greater than the first DC inductance L 1 The current i 1 , that is, the first power tube Q 1 Zero voltage turn-on condition;

[0117] In t 2 At this moment, the second power tube Q 2 Turn off, the first switch tube S 1 , the fourth switch tube S 4 、The fourth power tube Q 4 Keep it open, at this time, the transformer current i s Greater than the first DC inductance L 1 The current i 1 , in line with the first power tube Q 1 Zero voltage turn-on condition, the secondary side center point voltage v CD Transformed to V C3 ;

[0118] In t 3 At this moment, the first power tube Q 1 To achieve zero voltage switching, the first switch tube S 1 , the fourth switch tube S 4 、The fourth power tube Q 4 Keep the conduction state, at this time the voltage on both sides of the transformer is established, and energy begins to transfer from the primary side to the secondary side;

[0119] In t 4 At this moment, the fourth switch tube S 4 Turn off, the first switch tube S 1 , the first power tube Q 1 、The fourth power tube Q 4 Keep it turned on. At this time, the leakage current i p The polarity is positive and is stored in the third switch tube S 3 The energy in the parasitic junction capacitance is released. If the parameters are properly designed, the third switch tube S 3 The parasitic junction capacitance at t 4 ~t 5 The discharge is completed within the dead time, that is, the third switch tube S 3 Zero voltage switching;

[0120] In t 5 At this moment, the third switch tube S 3 To achieve zero voltage switching, the first switch tube S 1 , the first power tube Q 1 、The fourth power tube Q 4 Keep it open, in this additional working mode t 5 ~t 6 During this time, the leakage current i p Under the action of potential difference, it starts to decrease to reduce reactive current. To ensure leakage inductance L k Have enough energy to realize the second switch tube S 2 The zero voltage switch-on of the second additional mode lasts for td2 Reasonable design is required;

[0121] In t 6 At this moment, the first power tube Q 1 Turn off, the first switch tube S 1 , the third switch tube S 3 、The fourth power tube Q 4 Keep it turned on, the converted first DC inductance L 1 The current i 1 Much larger than the leakage inductance current i p , so the second power tube Q 2 Have the conditions for zero voltage switching;

[0122] In t 7 At this moment, the second power tube Q 2 To achieve zero voltage switching, the first switch tube S 1 , the third switch tube S 3 、The fourth power tube Q 4 Maintain opening;

[0123] t 7 ~t 8 It belongs to the reactive power 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 working principle of the second half cycle is not described in detail in the embodiment of the present invention.

[0125] like Figure 6 As shown, it is shown that when the battery is charged, the single-stage architecture divided-capacitance power supply provided by the embodiment of the present invention works at V 1 =750V, V 2 =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.

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

[0127] The third additional working mode is introduced to make the first switch tube S 1 Q than the first power tube 1 Duration of the first additional mode of hysteresis t d1 Turn on, or enable the second switch S 2 Q of the third power tube 3 Duration of the first additional mode of hysteresis t d1 Open;

[0128] The fourth additional working mode is introduced to make the third switch tube S 3 Than the second power tube Q 2 The duration of the second additional mode of hysteresis t d2 Turn on, or enable the fourth switch tube S 4 Q of the fourth power tube 4 The duration of the second additional mode of hysteresis t d2 Open.

[0129] In the embodiment of the present invention, the third additional working mode is that the second switch tube S 2 , the fourth switch tube S 4 , the first power tube Q 1 、The fourth power tube Q 4 In the on state, or the first switch tube S 1 , the third switch tube S 3 , the second power tube Q 2 、The third power tube Q 3 In the open state;

[0130] The fourth additional working mode is that the first switch tube S 1 , the fourth switch tube S 4 , the second power tube Q 2 、The fourth power tube Q 4 In the on state, or the second switch tube S 2 , the third switch tube S 3 , the second power tube Q 2 、The fourth power tube Q 4 In open state.

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

[0132]

[0133] Among them, L k Leakage inductance, L dc represents the DC inductance value, D represents the duty cycle, T s represents the switching cycle, n represents the transformer ratio, V 2 Indicates the voltage value of the battery cell, i o Represents the charge and discharge current, V 1 Indicates the high-voltage DC bus voltage.

[0134] Specifically, when the battery is discharged, 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] In t 0 At this moment, the second power tube Q 2 Turn off, the second switch tube S 2 , the fourth switch tube S 4 、The fourth power tube Q 4 Keep it open, at this time, the transformer current i s Greater than the first DC inductance L 1 The current i 1 , which means that the current polarity of the current difference between the two currents conforms to the first power tube Q 1 The body diode conduction direction, so the first power tube Q 1 It has the theoretical conditions to achieve zero voltage;

[0136] In t 1 At this moment, the first power tube Q 1 Achieved zero voltage turn-on, the second switch tube S 2 , the fourth switch tube S4 and the fourth power tube Q4 remain turned on, t 1 ~t 2 is the third additional working mode, and its duration is the duration of the first additional mode t d1 , in this stage, the primary neutral point v AB The voltage is V 1 / 2, 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 inductance current begins to decrease;

[0137] In t 2 At this moment, the second switch tube S 2 Turn off, the fourth switch tube S 4 , the first power tube Q 1 、The fourth power tube Q 4 Keep it turned on. At this time, the leakage current i p The polarity is negative, which can realize the first switch tube S 1 The discharge of the parasitic junction capacitance in the second switch tube S 2 The charging of the parasitic junction capacitance can be reduced within t 2 ~t 3 The first switch S is completed within the dead time. 1 Complete discharge of parasitic junction capacitance;

[0138] In t 3 At this moment, the first switch tube S 1 To achieve zero voltage switching, the fourth switch tube S 4 , the first power tube Q 1 、The fourth power tube Q 4Keep the conduction state. At this time, the voltage on both sides of the transformer is established, and the energy is transferred from the primary side to the secondary side.

[0139] In t 4 At this moment, the first power tube Q 1 Turn off, the first switch tube S 1 , the fourth switch tube S 4 、The fourth power tube Q 4 Keep it open. At this time, the converted first DC inductance L 1 The current i 1 Much larger than the leakage inductance current i p , which means that the second power tube Q 2 The energy in the parasitic junction capacitance can be fully released, that is, the second power tube Q 2 Have the basic conditions for zero voltage switching;

[0140] In t 5 At this moment, the second power tube Q 2 Achieved zero voltage turn-on, the first switch tube S 1 , the fourth switch tube S 4 、The fourth power tube Q 4 Keep it open, 5 ~t 6 It is the fourth additional working mode. In this stage, the primary neutral point voltage v AB The voltage is V 1 , secondary neutral point v CD The voltage is 0, the leakage current i p Under the action of the potential difference, it starts to decrease, and the duration of the second additional mode in this stage is reasonably designed. d2 Ensure the third switch tube S 3 Zero voltage realization conditions;

[0141] In t 6 At this moment, the fourth switch tube S 4 Turn off, the first switch tube S 1 , the second power tube Q 2 、The fourth power tube Q 4 Keep it turned on. At this time, the leakage current polarity is negative, which is consistent with the third switch tube S 3 The direction in which the body diode of the switch is naturally turned on means that the third switch tube S 3 It has the basic conditions for zero voltage switching.

[0142] In t 7 At this moment, the third switch tube S 3 Achieved zero voltage turn-on, the first switch tube S 1 , the second power tube Q 2 、The fourth power tube Q 4 Maintain opening;

[0143] t 7 ~t 8 It belongs to the reactive stage. During this stage, 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 repeat the working process of the second half cycle.

[0145] Fig. 9 It shows that when the battery is discharged, the single-stage architecture divided-capacitance power supply provided by the embodiment of the present invention works at V 1 =750V, V 2 =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 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; the voltage reference value of the battery cell is compared with the voltage value of the battery cell and then input into a first controller for calculation to obtain a 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 a second controller for calculation to obtain a 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 a third controller for calculation to obtain a first additional mode duration and a second additional mode duration; based on the first additional mode duration, the second additional mode duration and the duty cycle, a PWM signal generating unit is controlled to generate A first drive signal is generated for phase-shifting control of 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-doubler 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 need to be shut down to change the battery charging and discharging state, 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-doubler rectifier switch network, so as to realize zero-voltage turning-on of all switch tubes while reducing switching losses and 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 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 capacity-divided 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 inductance, 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 comprises: Step 1, obtaining a voltage reference value of the battery cell, a voltage value of the battery cell, a high-voltage DC bus voltage, and a 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 inputting the comparison results 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 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.

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 comprises: A first switch tube, a second switch tube, a third switch tube, a fourth switch tube, a first half-bridge capacitor and a second half-bridge capacitor; The drain of the first switch tube is respectively connected to the first end of the first half-bridge capacitor and the positive end of the high-voltage DC bus, the source of the first switch tube is connected to the drain of the second switch tube to form a first bridge arm, and the midpoint of the first bridge arm is connected to the first end of the leakage inductance; 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 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; The source of the fourth switch tube is respectively connected to the second end of the second half-bridge capacitor and the negative end of the high-voltage DC bus; The gate of the first switch tube, the gate of the second switch tube, the gate of the third switch tube, and the gate of the fourth switch 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 doubler rectifying switch network comprises: 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, and 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 respectively 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; 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 switch tube and the second switch tube are complementary; The driving signals of the third switch tube and the fourth switch 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 ratios of the driving signals of the first switch tube, the second switch tube, the third switch tube, and the fourth switch 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 working 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 structured 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 represents the DC inductance value, D represents 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 represents the charge and discharge current, and V1 represents the high-voltage DC bus voltage.

7. The control method of the single-stage structured capacity-divided power supply according to claim 4, characterized in that: When the battery is discharged, the single-stage architecture capacity-divided power supply 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; The fourth additional working mode is introduced to make the third switch tube turn on later than the second power tube by the second additional mode duration, or to make the fourth switch tube turn on later than the fourth power tube by the second additional mode duration.

8. The control method of the single-stage structured 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 represents the DC inductance value, D represents 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 represents the charge and discharge current, and V1 represents the high-voltage DC bus voltage.

9. The control method of the single-stage structured 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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