A method for regulating a propulsion system of a watercraft in all operating conditions

Abstract

The application discloses a kind of watercraft global operating condition propulsion system's regulation and control method, based on marine energy storage power supply, six-phase modular power electronic frequency converter and six-phase propulsion motor connection composition propulsion system, six-phase modular power electronic frequency converter front stage is set power electronic distribution module to realize input voltage conversion, and rear stage is set to realize the series-parallel switching of six-phase propulsion motor winding change-over switch;The application covers instruction preprocessing link, power distribution and winding change-over link and speed starting adaptive modulation link in regulation and control method, can be according to the running demand of watercraft, through the adaptive control of rated and through sailing condition, realize the efficient operation of propulsion system global operating condition, improve the self-sustaining force of watercraft.

Description

Technical Field

[0001] This invention belongs to the field of power electronics technology, specifically relating to a control method for a propulsion system of an underwater vehicle operating under all conditions. Background Technology

[0002] In specialized propulsion fields such as underwater vehicles, systems are typically designed based on rated operating conditions to achieve efficient operation under those conditions. Rated operating conditions correspond to high speeds, while navigation operating conditions correspond to low speeds, with a significant difference between the two. How to achieve high-efficiency control of the propulsion system under low-speed navigation conditions, while simultaneously meeting the operational requirements of both rated and navigation conditions, has become a major research hotspot in this field. Currently, domestic research on improving the efficiency of underwater vehicles under low operating conditions largely focuses on optimizing the maximum torque-to-current ratio (MTPA) control strategy and improving the motor's structural design. Progress in this area has been relatively slow, making it difficult to achieve breakthroughs in efficiency improvement.

[0003] Existing methods for improving the efficiency of underwater vehicles under low operating conditions still have significant limitations, failing to fully utilize the flexibility of power supply, motor, and frequency converter control. These limitations are mainly reflected in:

[0004] 1) The degree of freedom in input voltage regulation was not fully explored, and the technical path of improving the operating efficiency of the frequency converter side of the propulsion system by suppressing switching losses was ignored;

[0005] 2) The topological freedom of multiphase motors has not been effectively utilized, and a solution has not yet been explored to reduce the output phase current of the motor through topological reconfiguration by series and parallel connection on the output side of the frequency converter, thereby further improving the system's low-operating-condition efficiency. Summary of the Invention

[0006] The purpose of this invention is to address the above problems by proposing a control method for the propulsion system of an underwater vehicle under all operating conditions without significantly increasing the system complexity. Through energy scheduling, winding topology switching and adaptive modulation, a comprehensive electric propulsion system with high efficiency under all operating conditions can be achieved.

[0007] The technical solution adopted by this invention to solve its technical problem is: a control method for a propulsion system of an underwater vehicle operating under all conditions, based on a propulsion system composed of a marine energy storage power supply, a six-phase modular power electronic frequency converter, and a reconfigurable six-phase propulsion motor. The marine energy storage power supply provides two power interfaces through power supply one and power supply two connected in series. The six-phase modular power electronic frequency converter is equipped with a power electronic power distribution module at the front end to realize input voltage transformation, and a switching switch S at the rear end to realize the six-phase propulsion motor winding A1 - B1 - C1 - and A2 + B2 + C2 +The series-parallel switching is achieved by a power electronic distribution module consisting of switching transistors T1, T2, and T3, and diodes D1 and D2. Switch T1 is connected in series to the positive terminal of power supply one, switch T3 is connected in series to the negative terminal of power supply two, and switch T2 is connected in series to the connection point of power supply one and power supply two. Diode D1 is connected to switching transistors T1 and T2, and diode D2 is connected to switching transistors T2 and T3. The six-phase propulsion motor uses an open winding design to achieve series-parallel reconfiguration; the process includes the following steps:

[0008] Step 1, instruction preprocessing stage: Perform pulse blocking and flag setting operations before switching operating conditions based on the received instructions;

[0009] Step 2, power distribution and winding switching: Select the operating branch according to the switching flag and the power supply SOC status; when the switching flag is 1, close the switch tubes T1 and T3; when the switching flag is -1, select to close the switch tubes T1 and T2 or T2 and T3 according to the power supply SOC status.

[0010] Step 3, Adaptive Modulation for Speed ​​Start: Based on the current operating conditions, adaptive modulation of PWM for speed start is implemented. The corresponding initial output value for regulation is obtained through the current speed and bus voltage. The appropriate switching frequency is selected according to the current operating conditions of the motor to reduce switching losses and realize closed-loop control of the multi-phase motor.

[0011] Furthermore, step 1 specifically includes:

[0012] Step 1.1: Execute efficient control operations according to real-time operating condition commands: If the commands remain unchanged, switch the flag signal=0 and maintain the current state to exit control; if the operating condition commands change, execute the subsequent steps.

[0013] Step 1.2: Perform a shutdown operation and apply a PWM modulation blocking pulse;

[0014] Step 1.3: Block the switching transistors T1, T2, T3 and the switching switch S;

[0015] Step 1.4: If the current operation needs to be switched from small operating condition to large operating condition, the switching flag signal=1; if the current operation needs to be switched from large operating condition to small operating condition, the switching flag signal=-1.

[0016] Furthermore, step 2 specifically includes:

[0017] Step 2.1: Execute the subsequent operation based on the switching flag signal. If the switching flag signal=1, then execute step 2.2; if the switching flag signal=-1, then execute step 2.3.

[0018] Step 2.2: Switches T1 and T3 are turned on, the maximum voltage is output, and the process jumps to step 3.

[0019] Step 2.3: Switch S is turned on to increase the back electromotive force of the motor at low speed;

[0020] Step 2.4: Select the switching transistors to be turned on according to the power supply status: if the SOC of power supply one is greater than the SOC of power supply two, switch transistors T1 and T2 are turned on; otherwise, switch transistors T2 and T3 are turned on.

[0021] Furthermore, step 3 specifically includes:

[0022] Step 3.1, using the current rotational speed n and bus voltage u dc The initial output value u corresponding to this operating condition is obtained by looking up a table. dq0 The calculation formula is: , where u dc_table n table and u dq0_table The reference values ​​for bus voltage, speed, and control are obtained from the tables;

[0023] Step 3.2: Select a suitable switching frequency ƒ based on the current operating requirements of the motor. c This further reduces switching losses.

[0024] The first and second power sources are battery clusters.

[0025] The aforementioned switching transistors T1 and T2 are high-frequency switching devices such as third-generation SiC and GaN.

[0026] The aforementioned switching transistor T3 is composed of IGBTs connected in series in reverse phase.

[0027] The switching switch S is a device such as a contactor, circuit breaker, IGBT, or thyristor.

[0028] The beneficial effects of this invention are as follows: This invention combines the optimization of the power distribution topology and motor winding topology of the underwater vehicle system. Based on the existing propulsion frequency converter, it realizes the functions of power electronic power distribution and winding switching by adding power electronic devices; it makes full use of the freedom of battery voltage and multi-phase motor output, as well as the rapid action of power electronic devices, to balance the contradiction between equipment operating efficiency, control performance and overall requirements, further expands the control ideas, and is highly practical and easy to implement in engineering; the method of this invention can achieve high-efficiency operation of the propulsion system in all operating conditions according to the operating requirements of the underwater vehicle through adaptive regulation under rated and transit conditions, thereby improving the self-sufficiency of the underwater vehicle. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the propulsion system of the present invention;

[0030] Figure 2This is a schematic diagram of the power electronic distribution and winding switching principle of the present invention;

[0031] Figure 3 This is a schematic diagram of the control method of the present invention.

[0032] The attached figures are labeled as follows: 01—Marine energy storage power supply, 02—Six-phase modular power electronic frequency converter, 03—Six-phase propulsion motor. Detailed Implementation

[0033] The specific embodiments of the present invention will now be described in conjunction with the accompanying drawings and examples.

[0034] This invention addresses the need for high-efficiency control across the entire range of operating conditions for integrated electric propulsion in underwater vehicles, specifically under both rated and conventional propulsion conditions. It provides a high-efficiency propulsion system for underwater vehicles operating under all operating conditions. Through coordinated control of the power supply, motor, and frequency converter, it achieves optimal efficiency. This system is applicable to power conversion modules using third-generation SiC, GaN, and other high-frequency switching devices, and is particularly suitable for integrated electric propulsion applications where there is a significant deviation between rated and conventional operating conditions.

[0035] This invention discloses a method for controlling the propulsion system of an underwater vehicle under all operating conditions, such as... Figure 1 As shown, the propulsion system for high-efficiency propulsion in all operating conditions of an all-electric ship consists of a marine energy storage power supply 01, a six-phase modular power electronic frequency converter 02, and a reconfigurable open-winding six-phase propulsion motor 03.

[0036] In terms of system architecture, the marine energy storage power supply 01 has two power interfaces, namely power supply one and power supply two, which are battery clusters connected in series.

[0037] The six-phase modular power electronic frequency converter 02 is equipped with a power electronic power distribution module in the front stage to realize input voltage transformation, and a switching switch S in the rear stage to realize the series-parallel switching of the windings of the six-phase propulsion motor 03.

[0038] The power electronic distribution module consists of switching transistors T1, T2, and T3, and diodes D1 and D2. Switch T1 is connected in series to the positive terminal of power supply one; switch T3 is connected in series to the negative terminal of power supply two; switch T2 is connected in series to the junction of power supply one and power supply two; diode D1 connects to switches T1 and T2; diode D2 connects to switches T2 and T3; and diodes D1 and D2 are connected in parallel on the power output side to prevent direct current flow during transient processes of switches T1, T2, and T3. When switches T1 and T2 are on, power supply one is powered; when switches T2 and T3 are on, power supply two is powered; when switches T1 and T3 are on, power supply one and power supply two are powered simultaneously. Switch T3 is composed of IGBTs connected in series in reverse phase.

[0039] The switching switch S enables the switching function of the six-phase propulsion motor 03, wherein the switching transistor is connected to the open winding motor A1.- B1 - C1 - and A2 + B2 + C2 + At low speeds, the back electromotive force of the propulsion motor is increased by connecting the windings in series, which can be achieved by devices such as contactors, circuit breakers, IGBTs or thyristors.

[0040] The six-phase propulsion motor 03 uses an open winding design to achieve series-parallel reconfiguration.

[0041] This invention achieves efficient regulation across the entire range through the coordinated control of marine energy storage power supply, multiphase modular power electronic frequency converter and reconfigurable multiphase propulsion motor. It can achieve high-efficiency operation of the propulsion system across the entire range of operating conditions according to the operating requirements of all-electric ships through adaptive regulation under rated and navigation conditions, thereby improving the self-sufficiency of all-electric propulsion ships.

[0042] In terms of control methods, this invention covers the command preprocessing stage, the power distribution and winding switching stage, and the belt-speed start-up adaptive modulation stage. For example... Figure 2 and Figure 3 As shown, it includes the following steps.

[0043] Step 1, instruction preprocessing stage.

[0044] Based on the received instructions, perform the blocking pulse and flag setting operations before switching operating conditions. The specific operations are as follows.

[0045] Step 1.1: Execute efficient control operations according to real-time operating condition commands: If the command remains unchanged, switch the signal flag to 0, maintain the current state, and exit control; if the operating condition command changes, execute the subsequent steps.

[0046] Step 1.2: Perform a shutdown operation and apply a PWM modulation blocking pulse.

[0047] Step 1.3: Block the switching tubes T1, T2, T3 and the switching switch S.

[0048] Step 1.4: If the current operating condition needs to be upgraded from a small operating condition to a large operating condition, the switching flag signal=1; if the current operating condition needs to be upgraded from a large operating condition to a small operating condition, the switching flag signal=-1.

[0049] Step 2, power distribution and winding switching.

[0050] The operating branch is selected based on the switching flag and the power supply SOC status: when the switching flag is 1, switches T1 and T3 are closed; when the switching flag is -1, switches T1 and T2 or T2 and T3 are closed based on the power supply SOC status. The specific operation is as follows.

[0051] Step 2.1: Execute the subsequent operation based on the switching flag signal. If the switching flag signal=1, then execute step 2.2; if the switching flag signal=-1, then execute step 2.3.

[0052] Step 2.2: Switches T1 and T3 are turned on, the maximum voltage is output, and the process jumps to step 3.

[0053] Step 2.3: Turn on the switching switch S to increase the back electromotive force of the motor at low speed.

[0054] Step 2.4: Select the switching transistors to be turned on according to the power supply status. If the SOC of power supply one is greater than the SOC of power supply two, switching transistors T1 and T2 are turned on; otherwise, switching transistors T2 and T3 are turned on.

[0055] Step 3: Speed-start adaptive modulation stage.

[0056] Based on the current operating conditions, speed-start PWM adaptive modulation is implemented, and the corresponding initial output value for regulation is obtained from the current speed and bus voltage. Select the appropriate switching frequency based on the current operating conditions of the motor. This reduces switching losses. The specific steps are as follows.

[0057] Step 3.1, using the current rotational speed n and bus voltage u dc The initial output value u corresponding to this operating condition is obtained by looking up a table. dq0 The calculation formula is: , where u dc_table n table and u dq0_table The reference values ​​for bus voltage, speed, and control are obtained by looking up the tables.

[0058] Step 3.2: Select a suitable switching frequency ƒ based on the current operating requirements of the motor. c This further reduces switching losses.

[0059] The specific embodiments described herein are merely illustrative examples illustrating the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A method for controlling the propulsion system of an underwater vehicle under all operating conditions, characterized in that: The propulsion system is composed of a marine energy storage power supply (01), a six-phase modular power electronic frequency converter (02), and a six-phase propulsion motor (03). The marine energy storage power supply (01) provides two power interfaces through power supply one and power supply two connected in series. The six-phase modular power electronic frequency converter (02) is equipped with a power electronic power distribution module at the front end to realize input voltage transformation, and a switching switch S is set at the rear end to realize the winding A1 of the six-phase propulsion motor (03). - B1 - C1 - and A2 + B2 + C2 + The series-parallel switching of the power electronic distribution module consists of switching transistors T1, T2, and T3, and diodes D1 and D2. Switch T1 is connected in series to the positive terminal of power supply one, switch T3 is connected in series to the negative terminal of power supply two, and switch T2 is connected in series to the connection point of power supply one and power supply two. Diode D1 is connected to switching transistors T1 and T2, and diode D2 is connected to switching transistors T2 and T3. The six-phase propulsion motor (03) achieves series-parallel reconfiguration through an open winding design; including the following steps. Step 1: Perform the blocking pulse and flag setting operations before the operating condition switch according to the received instructions; Step 2: Select the operating branch based on the switching flag and power SOC status; Step 3: Implement speed-start PWM adaptive modulation based on the current operating conditions. Obtain the corresponding initial output value for regulation through the current speed and bus voltage. Select an appropriate switching frequency according to the current operating conditions of the motor to achieve closed-loop control of the multi-phase motor.

2. The control method for an underwater vehicle's propulsion system under all operating conditions according to claim 1, characterized in that, Step 1 specifically includes: Step 1.1: Execute efficient control operations according to real-time operating condition commands: If the commands remain unchanged, switch the flag signal=0 and maintain the current state to exit control; if the operating condition commands change, execute the subsequent steps. Step 1.2: Perform a shutdown operation and apply a PWM modulation blocking pulse; Step 1.3: Block the switching transistors T1, T2, T3 and the switching switch S; Step 1.4: If the current operation needs to be switched from small operating condition to large operating condition, the switching flag signal=1; if the current operation needs to be switched from large operating condition to small operating condition, the switching flag signal=-1.

3. The control method for an underwater vehicle's propulsion system under all operating conditions according to claim 2, characterized in that, Step 2 specifically includes: Step 2.1: Execute the subsequent operation based on the switching flag signal. If the switching flag signal=1, then execute step 2.2; if the switching flag signal=-1, then execute step 2.

3. Step 2.2: Switches T1 and T3 are turned on, the maximum voltage is output, and the process jumps to step 3. Step 2.3: Switch S is turned on to increase the back electromotive force of the motor at low speed; Step 2.4: Select the switching transistors to be turned on according to the power supply status: if the SOC of power supply one is greater than the SOC of power supply two, switch transistors T1 and T2 are turned on; otherwise, switch transistors T2 and T3 are turned on.

4. The control method for an underwater vehicle's all-terrain propulsion system according to claim 3, characterized in that, Step 3 specifically includes: Step 3.1, using the current rotational speed n and bus voltage u dc Calculate the initial output value of the control system corresponding to this operating condition. , where u dc_table n table and u dq0_table The reference values ​​for bus voltage, speed, and control are obtained from the tables; Step 3.2: Select a suitable switching frequency ƒ based on the current operating requirements of the motor. c .

5. The control method for an underwater vehicle's propulsion system under all operating conditions according to claim 4, characterized in that, The first and second power sources are battery clusters.

6. The control method for an underwater vehicle's all-terrain propulsion system according to claim 4, characterized in that, The switching transistors T1 and T2 are made of SiC or GaN.

7. The control method for an underwater vehicle's propulsion system under all operating conditions according to claim 4, characterized in that, The aforementioned switching transistor T3 is composed of IGBTs connected in series in reverse phase.

8. The control method for an underwater vehicle's all-terrain propulsion system according to claim 4, characterized in that, The switching switch S is a contactor, circuit breaker, IGBT, or thyristor.

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