A high-efficiency control method for an H-bridge cascaded topology

Abstract

The application provides a high-efficiency control method for H-bridge cascaded topology, belongs to the field of power electronics and control technology, and the driven H-bridge cascaded topology comprises n H-bridges H1, H2,..., Hn; the i-th H-bridge comprises four switching tubes T1i, T2i, T3i and T4i; the left bridge arm comprises the switching tubes T1i and T2i; the right bridge arm comprises the switching tubes T3i and T4i; the high-efficiency control method for the H-bridge cascaded topology comprises a switching tube driving strategy and a driving signal group moving strategy; the switching tube driving strategy is that at least two driving signals are used to drive the n H-bridges; and the driving signal group moving strategy is that every time interval, the driving signals of each H-bridge are exchanged. The application reduces the switching loss of the H-bridge cascaded topology by setting slow tubes and specific driving generation modes and driving group cycle moving schemes, reduces the heat generation by nearly 50%, and improves the efficiency.

Description

Technical Field

[0001] This invention relates to the field of power electronics and control technology, specifically to a high-efficiency control method for H-bridge cascaded topology. Background Technology

[0002] H-bridge cascade technology, due to its unique characteristics such as high output frequency, high output voltage, and independent bus, is widely used in fields such as static var generators, inverters, energy storage devices, and ripple generators. Published technologies CN216672976U, CN116148698A, and CN115776218A all utilize H-bridge cascade topologies. The paper "Research on H-bridge Cascaded Multilevel Inverter Circuit and Its Applications" also applies the H-bridge cascade topology as an inverter.

[0003] Because cascaded H-bridge inverters contain multiple power units, each requiring thermal management, the complexity of system thermal management increases. In this case, if the cascaded H-bridge topology employs all-fast transistor control, meaning all switches operate at high frequencies, the high-frequency switching leads to higher switching losses, causing the switches to generate significant heat, which is ultimately dissipated. This sustained high-temperature environment can affect the lifespan and reliability of the switches and other power electronic components. To address this high heat dissipation and the uneven heat distribution that may result from varying voltage and current stresses on different power devices, more advanced heat dissipation technologies, such as liquid cooling systems or specialized thermal management strategies, are needed to ensure system thermal uniformity. This significantly increases system cost and maintenance complexity. Summary of the Invention

[0004] This invention aims to propose a new control method for H-bridge cascaded topology, from the perspective of high-efficiency control methods, to reduce the switching losses of switching devices in H-bridge cascaded topology and improve the efficiency of H-bridge cascaded topology.

[0005] To achieve the above objectives, the present invention employs the following technical solution:

[0006] A high-efficiency control method for H-bridge cascade topology is provided. The driven H-bridge cascade topology includes n H-bridges H1, H2...Hn. The i-th H-bridge includes four switches T1i, T2i, T3i, and T4i. The left bridge arm includes switches T1i and T2i, and the right bridge arm includes switches T3i and T4i. The high-efficiency control method for H-bridge cascade topology includes a switch driving strategy and a driving signal group movement strategy.

[0007] The switching transistor driving strategy is to drive n H-bridges using at least two types of driving signals;

[0008] The drive signal group movement strategy is as follows: every certain period of time, the drive signals of each H-bridge are exchanged.

[0009] Furthermore, n is an even number, drive group S(2k+1) and drive group S(2k+2) are the drive signals for the (2k+1)th and (2k+2)th H-bridges in the initial state, and k is a non-negative integer, where 0 < 2k+1. <n;

[0010] The drive group S(2k+1) includes drive signals: S1(2k+1), S2(2k+1), S3(2k+1), S4(2k+1), which control the switching transistors T1(2k+1), T2(2k+1), T3(2k+1), and T4(2k+1) in the 2k+1th H-bridge, respectively.

[0011] The drive group S(2k+2) includes drive signals: S1(2k+2), S2(2k+2), S3(2k+2), S4(2k+2), which control the switching transistors T1(2k+2), T2(2k+2), T3(2k+2), and T4(2k+2) in the 2k+2th H-bridge, respectively.

[0012] Furthermore, the driving signal is generated by comparing the carrier wave uc(2k+1), the carrier wave uc(2k+2), and the modulated wave us;

[0013] The driving group S(2k+1) is generated by comparing the carrier wave uc(2k+1) with the modulated wave us;

[0014] The driving group S(2k+2) is generated by comparing the carrier wave uc(2k+2) with the modulated wave us.

[0015] Furthermore, the driving signal of the driving group S(2k+1) is generated as follows: when the modulation wave us>0, S1(2k+1)=1; when the modulation wave us<0, S1(2k+1)=0.

[0016] S2(2k+1) and S1(2k+1) are complementary;

[0017] When the modulated wave us > uc (2k+1), S4(2k+1) = 1; when us < uc (2k+1), S4(2k+1) = 0;

[0018] S3(2k+1) and S4(2k+1) are complementary;

[0019] The driving signal of the driving group S(2k+2) is generated as follows: when the modulation wave us>0, S4(2k+2)=1; when the modulation wave us<0, S4(2k+2)=0.

[0020] S3(2k+2) and S4(2k+2) are complementary;

[0021] When the modulated wave us > uc (2k+2), S1(2k+2) = 1; when us < uc (2k+2), S1(2k+2) = 0;

[0022] S2(2k+2) and S1(2k+2) are complementary.

[0023] Furthermore, the phase difference between carrier uc(2k+1) and carrier uc(2k+2) is 2π / n degrees.

[0024] Furthermore, the driving signal group movement strategy is as follows:

[0025] Set a periodic trigger condition, and when trigger is triggered, the driver group Si of the i-th H-bridge in the previous cycle is changed to drive the (i+1)-th H-bridge, and the driver group Sn of the n-th H-bridge in the previous cycle is changed to drive the 1-th H-bridge.

[0026] Furthermore, the trigger condition is the zero-crossing point of the modulated wave from negative to positive.

[0027] Furthermore, after each trigger condition arrives, all switches are turned off for a time td before the drive signal is exchanged according to the drive signal group movement strategy. The time td ranges from 100ns to 1μs.

[0028] The advantages of this invention are:

[0029] This invention reduces switching losses in H-bridge cascaded topologies by setting a slow transistor, a specific drive generation method, and a cyclic movement scheme for the drive group, resulting in a nearly 50% reduction in heat generation and improved efficiency. The above technical solution allows the two arms of each H-bridge to exchange fast and slow transistors every cycle; in one cycle, the left arm is the fast transistor and the right arm is the slow transistor, and in the next cycle, the left arm is the slow transistor and the right arm is the fast transistor. This balances the heat generation of the two arms of each H-bridge, avoiding the uneven heat generation problem that would result from reduced heat generation, where the slow transistor is not hot while the fast transistor is very hot. This ensures balanced heating of the switching transistors in both arms of the H-bridge, further reducing the heat stress on the switching transistors and contributing to increased switching frequency. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the high-efficiency control method for H-bridge cascaded topology of the present invention;

[0031] Figure 2 This is a schematic diagram illustrating the triggering conditions of the present invention.

[0032] Figure 3 This is a schematic diagram of the carrier and driving principle of adjacent odd-numbered H-bridges and even-numbered H-bridges in this invention;

[0033] Figure 4 This is a circuit diagram of the H-bridge cascaded topology of the present invention. Detailed Implementation

[0034] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0035] This embodiment discloses a high-efficiency control method for an H-bridge cascaded topology. The driven H-bridge cascaded topology includes n H-bridges H1, H2...Hn. The i-th H-bridge includes four switches T1i, T2i, T3i, and T4i. The left bridge arm includes switches T1i and T2i, and the right bridge arm includes switches T3i and T4i. The n H-bridges are connected in series. Please refer to [reference needed]. Figure 4 In bridge H1, the midpoint A1 of the left bridge arm is connected to the left end of inductor L; the midpoint B1 of the right bridge arm is connected to the midpoint of the left bridge arm of bridge H2; the midpoint B2 of the right bridge arm is connected to the midpoint of the left bridge arm of bridge H3; ... the right bridge arm Bn-1 of bridge Hn-1 is connected to the midpoint of the left bridge arm of bridge Hn; the midpoint Bn of the right bridge arm of bridge Hn is connected to one end of uo; and the other end of uo is connected to the right end of inductor L.

[0036] For an even number of H-bridges in an H-bridge cascade topology, please refer to [reference needed]. Figure 3 The control methods include switching transistor driving strategies and driving signal group movement strategies;

[0037] The switching transistor driving strategy is to drive n H-bridges using at least two types of driving signals;

[0038] The drive signal group movement strategy is as follows: every certain period of time, the drive signals of each H-bridge are exchanged.

[0039] Initially, drive groups S(2k+1) and S(2k+2) are the drive signals for the (2k+1)th and (2k+2)th H-bridges, respectively, where k is a non-negative integer and 0 < 2k+1. <n。

[0040] The drive group S(2k+1) includes drive signals: S1(2k+1), S2(2k+1), S3(2k+1), S4(2k+1), which control the switching transistors T1(2k+1), T2(2k+1), T3(2k+1), and T4(2k+1) in the 2k+1th H-bridge, respectively.

[0041] The drive group S(2k+2) includes drive signals: S1(2k+2), S2(2k+2), S3(2k+2), S4(2k+2), which control the switching transistors T1(2k+2), T2(2k+2), T3(2k+2), and T4(2k+2) in the 2k+2th H-bridge, respectively.

[0042] The phase difference between carrier uc(2k+1) and carrier uc(2k+2) is 2π / n degrees. The driving signal is generated by comparing carrier uc(2k+1) and carrier uc(2k+2) with the modulated wave.

[0043] The driving signal generation method of the driving group S(2k+1) is as follows: when the modulation wave us > 0, S1(2k+1) = 1; when the modulation wave us < 0, S1(2k+1) = 0; S2(2k+1) is complementary to S1(2k+1); when the modulation wave us > uc(2k+1), S4(2k+1) = 1; when us < uc(2k+1), S4(2k+1) = 0; S3(2k+1) is complementary to S4(2k+1).

[0044] The driving signal of the driving group S(2k+2) is generated as follows: when the modulation wave us>0, S4(2k+2)=1; when the modulation wave us<0, S4(2k+2)=0; S3(2k+2) and S4(2k+2) are complementary; when the modulation wave us>uc(2k+2), S1(2k+2)=1; when us<uc(2k+2), S1(2k+2)=0; when S2(2k+2) and S1(2k+2) are complementary.

[0045] Please refer to Figure 2 A periodic trigger condition, `triger`, is set, with the zero-crossing point of the modulated wave from negative to positive as the trigger condition. Each time `triger` is triggered, the driving group Si of the i-th H-bridge in the previous cycle is changed to drive the (i+1)-th H-bridge, and the driving group Sn of the n-th H-bridge in the previous cycle is changed to drive the 1st H-bridge. That is, refer to... Figure 1 Initially, the driving group S1 drives H1, driving group S2 drives H2, driving group S(2k+1) drives H(2k+1), driving group S(2k+2) drives H(2k+2), and driving group Sn drives Hn, where n is an even number. When the first trigger condition (triger1) arrives, driving group S1 drives H2, driving group S2 drives H3, driving group S(2k+1) drives H(2k+2), driving group S(2k+2) drives H(2k+3), and driving group Sn drives H1. When the second trigger condition (triger2) arrives, driving group S1 drives H3, driving group S2 drives H4, driving group S(2k+1) drives H(2k+3), driving group S(2k+2) drives H(2k+4), driving group S(n-1) drives H1, and driving group Sn drives H2. This cycle repeats.

[0046] After each trigger condition arrives, all switches are turned off for a time td before the drive signal is exchanged according to the drive signal group movement strategy. The td time range is 100ns~1μs, which is determined by the type of switching device.

[0047] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-efficiency control method for an H-bridge cascaded topology, wherein the driven H-bridge cascaded topology includes n H-bridges H1, H2...Hn, the i-th H-bridge includes four switches T1i, T2i, T3i, and T4i, the left bridge arm includes switches T1i and T2i, and the right bridge arm includes switches T3i and T4i, characterized in that, The high-efficiency control method for the H-bridge cascaded topology includes a switching transistor driving strategy and a driving signal group movement strategy. The switching transistor driving strategy is to drive n H-bridges using at least two types of driving signals. The driving signal group movement strategy is as follows: every certain period of time, the driving signals of each H-bridge are exchanged. n is an even number, drive group S(2k+1) and drive group S(2k+2) are the drive signals of the (2k+1)th and (2k+2)th H-bridges in the initial state, k is a non-negative integer, and 0 < 2k+1. <n; The drive group S(2k+1) includes drive signals: S1(2k+1), S2(2k+1), S3(2k+1), S4(2k+1), which control the switching transistors T1(2k+1), T2(2k+1), T3(2k+1), and T4(2k+1) in the 2k+1th H-bridge, respectively. The drive group S(2k+2) includes drive signals: S1(2k+2), S2(2k+2), S3(2k+2), S4(2k+2), which control the switching transistors T1(2k+2), T2(2k+2), T3(2k+2), and T4(2k+2) in the 2k+2th H-bridge, respectively. The driving signal is generated by comparing the carrier wave uc(2k+1), the carrier wave uc(2k+2), and the modulated wave us; The driving group S(2k+1) is generated by comparing the carrier wave uc(2k+1) with the modulated wave us; The drive group S(2k+2) is generated by comparing the carrier wave uc(2k+2) with the modulated wave us; The driving signal of the driving group S(2k+1) is generated in the following ways: when the modulation wave us>0, S1(2k+1)=1; when the modulation wave us<0, S1(2k+1)=0. S2(2k+1) and S1(2k+1) are complementary; When the modulated wave us > uc (2k+1), S4(2k+1) = 1; when us < uc (2k+1), S4(2k+1) = 0; S3(2k+1) and S4(2k+1) are complementary; The driving signal of the driving group S(2k+2) is generated as follows: when the modulation wave us>0, S4(2k+2)=1; when the modulation wave us<0, S4(2k+2)=0. S3(2k+2) and S4(2k+2) are complementary; When the modulated wave us > uc (2k+2), S1(2k+2) = 1; when us < uc (2k+2), S1(2k+2) = 0; S2(2k+2) and S1(2k+2) are complementary; The driving signal group movement strategy is as follows: Set a periodic trigger condition, and when trigger is triggered, the driver group Si of the i-th H-bridge in the previous cycle is changed to drive the (i+1)-th H-bridge, and the driver group Sn of the n-th H-bridge in the previous cycle is changed to drive the 1-th H-bridge.

2. The high-efficiency control method for H-bridge cascaded topology according to claim 1, characterized in that, The phase difference between carrier uc(2k+1) and carrier uc(2k+2) is 2π / n degrees.

3. The high-efficiency control method for H-bridge cascaded topology according to claim 1, characterized in that, The trigger condition is the zero-crossing of the modulated wave from negative to positive.

4. The high-efficiency control method for H-bridge cascaded topology according to claim 1, characterized in that, After each trigger condition arrives, all switches are turned off for a time td before the drive signals are exchanged according to the drive signal group movement strategy. The time td ranges from 100ns to 1μs.

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