A hybrid intelligent power generation collaborative control method based on a position sensorless motor control

Abstract

The application aims to provide a hybrid intelligent power generation collaborative control method based on a position sensorless motor control, comprising an ammonia fuel engine and a three-phase permanent magnet synchronous motor. In order to overcome the sensor redundancy caused by the individual control of the two, an active flux linkage observer is used to estimate the motor rotor angle, and an extended state observer is used to estimate the motor speed and load torque. The motor speed is used to estimate the engine speed, and the motor rotor position is used to estimate the crankshaft angle position, so as to save the cost of the engine crankshaft sensor and be applicable to mass production.

Description

Technical Field

[0001] The present invention relates to a ship control method, specifically a ship hybrid power control method. Background Technology

[0002] Currently, marine power systems, which are mainly based on diesel engines, have the disadvantages of high pollution, low energy consumption, and high carbon emissions. Therefore, there is an urgent need to find a low-carbon and efficient power system to meet the increasingly stringent carbon reduction requirements and adapt to the future goals of low-carbonization and even zero carbon.

[0003] Ammonia fuel, as a clean fuel, is widely used in the chemical industry. As a zero-carbon fuel, it has also attracted increasing attention in the marine propulsion field in recent years. Although the concept of ammonia fuel engines has been proposed in the shipbuilding industry, mature products are still lacking due to technological limitations. On the one hand, there is a lack of comprehensive research on the performance of ammonia fuel engines; on the other hand, there is no clear technical solution for matching ammonia fuel engines with appropriate power systems. Therefore, the research and development of ammonia fuel engines is still in its initial stage, and hybrid power systems for ammonia fuel engines are currently a technological void.

[0004] Marine hybrid power systems combine the advantages of traditional internal combustion engine propulsion and pure electric propulsion. Hybrid systems offer significant advantages in overall energy efficiency, energy conservation and emission reduction, and vibration and noise reduction. Furthermore, compared to pure electric propulsion systems, they can achieve long driving ranges with smaller capacity batteries at a lower cost. Hybrid systems based on ammonia fuel engines can meet the requirements of zero-carbon power while mitigating the low efficiency and cold-start difficulties of ammonia fuel engines. The introduction of an electric motor can also improve the dynamic characteristics of ammonia fuel engines, achieving complementary advantages from multiple power sources. Hybrid systems based on ammonia fuel engines will become one of the best power forms for future zero-carbon power.

[0005] Currently, power generation units based on ammonia fuel engines simply mechanically couple the ammonia fuel engine and the motor. Their control methods are completely independent of each other, which leads to uncoordinated control and wasted hardware. At the same time, the power generation unit as a whole needs to be coordinated and controlled as a whole to maximize its advantages. Summary of the Invention

[0006] The purpose of this invention is to provide a hybrid intelligent power generation cooperative control method based on sensorless motor control that can overcome the shortcomings of traditional hybrid power generation units where the engine and motor are controlled separately, resulting in poor control performance.

[0007] The objective of this invention is achieved as follows:

[0008] The present invention discloses a hybrid power generation intelligent collaborative control method based on sensorless motor control, characterized in that it includes an ammonia fuel engine and a three-phase permanent magnet synchronous motor, wherein the ammonia engine adopts speed control and the three-phase permanent magnet synchronous motor adopts torque control.

[0009] The speed control of a three-phase permanent magnet synchronous motor includes an active flux observer, a speed observer, a torque PID loop, and a current PID loop. The active flux observer estimates the motor angle, the speed observer observes the speed and load torque, and the torque PID loop and the current PID loop control the motor speed and current in a dual-loop manner.

[0010] The expression for the active flux observer is:

[0011]

[0012]

[0013] ψ CM =K active ψ2|ψ2| -1

[0014] ψ VM =∫u-Ri+w v dt+L q i

[0015]

[0016]

[0017] The expression for the rotational speed observer is:

[0018]

[0019]

[0020]

[0021]

[0022] Where: K active For active flux; L d It is a direct-axis inductor; L q For axial inductance; r req For virtual resistance; i d For stator direct-axis current; i q For stator quadrature-axis current; K E ψ1 is the stator flux linkage; u is the stator voltage; i is the stator current; w v For interference; k p k is the scaling factor for the flux linkage observer. iψ is the integral coefficient; ψ2 is the active flux vector; ψ CM For the current model, the corresponding magnetic flux linkage is ψ. VM For the magnetic flux corresponding to the voltage model; Quadrature axis current estimate; n is the estimated motor speed. pp J represents the number of pole pairs of the motor. s This refers to the moment of inertia of the motor. K is the estimated load torque value. p K is the proportional coefficient of the speed observer; i K is the integral coefficient; d These are the differential coefficients; ε is the quadrature-axis voltage; ε is the error operator.

[0023] The present invention may also include:

[0024] 1. The center line of the shaft corresponding to the wide tooth gap of the flywheel signal disk in the ammonia fuel engine is aligned with the spatial position axis of phase A of the stator winding of the three-phase permanent magnet synchronous motor. In the three-phase coordinate system and the quadrature-direct axis coordinate system, phase A is aligned with the direct axis; at the same time, the crankshaft sensor of the ammonia fuel engine is eliminated.

[0025] 2. The ammonia fuel engine employs a speed control method. The difference between the estimated engine speed and the given speed is used, with coolant temperature and speed error as inputs. The PID coefficients are determined by looking up tables in the proportional system MAP, integral coefficient, and derivative coefficient tables. After PID calculation, these are accumulated to obtain the speed-regulating ammonia injection quantity. The no-load ammonia injection quantity is obtained by looking up the table with coolant temperature as input. The feedforward ammonia injection quantity is dynamically corrected by looking up the table with the converted estimated engine speed and torque as inputs. Finally, the speed-regulating ammonia injection quantity, the feedforward quantity, and the no-load ammonia injection quantity are accumulated to obtain the ammonia injection quantity required for the final controlled speed.

[0026] 3. The conversion relationship between the estimated speed of the ammonia fuel engine and the estimated speed of the electric motor is as follows:

[0027]

[0028] Where: n e For ammonia fuel engine speed; θ e This refers to the crankshaft rotation angle; Estimate the angle of the motor rotor; T e For engine torque; η m For motor efficiency.

[0029] The advantages of this invention are:

[0030] 1. This invention proposes a hybrid intelligent power generation unit and cooperative control method based on sensorless motor control. In terms of hardware design, the crankshaft sensor of the ammonia fuel engine is eliminated. Instead, the center line of the wide-toothed signal disk at the crankshaft flywheel end is aligned with the spatial axis A of the three-phase permanent magnet motor. This design allows the crankshaft angle of the ammonia engine to be calculated from the position of the motor rotor without complex conversions. This saves on sensor hardware costs and significantly reduces the signal processing load on the engine controller, saving computational space.

[0031] 2. The collaborative control strategy of the hybrid intelligent power generation unit adopts engine speed control and motor torque control, which fully considers the dynamic characteristics of both. That is, it takes advantage of the motor's fast dynamic response to quickly reach the required torque and has a good response to transient power loads.

[0032] 3. The three-phase permanent magnet synchronous motor adopts a sensorless control method, which uses active flux to observe the rotor angle and uses an extended state observer to estimate the motor speed and torque. The estimated torque of the motor can be used as a feedforward input for the ammonia fuel engine, which greatly improves the dynamic response of the ammonia engine. At the same time, the sensorless observation control method saves the motor torque sensor, which saves two sensors for the entire power unit and reduces hardware costs.

[0033] 4. This invention uses an ammonia fuel engine, which is clean and low-carbon, in line with the development direction of green ships. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the control structure of the present invention;

[0035] Figure 2 This is a hardware structure layout diagram of the present invention. Detailed Implementation

[0036] The invention will now be described in more detail with reference to the accompanying drawings:

[0037] Combination Figure 1-2 This invention discloses a collaborative control method for a hybrid intelligent power generation unit based on sensorless motor control, including PID proportional coefficient MAP1, integral coefficient MAP2, derivative coefficient MAP3, no-load ammonia injection quantity MAP4, and feedforward ammonia injection quantity dynamic correction lookup table 5 in the ammonia fuel engine control; and speed observer 6, torque PID 7, current PID 8, active flux observer 9, SVPWM module 10, and inverter 11 in the three-phase permanent magnet synchronous motor control.

[0038] In the intelligent power generation unit, the center line of the shaft corresponding to the wide tooth gap of the flywheel signal disk in the ammonia fuel engine is aligned with the spatial position axis of phase A of the stator winding of the three-phase permanent magnet synchronous motor. At the same time, phase A is aligned with the direct axis in both the three-phase coordinate system and the quadrature-direct axis coordinate system. Meanwhile, the crankshaft sensor of the ammonia fuel engine is eliminated.

[0039] The ammonia engine uses speed control, while the three-phase permanent magnet synchronous motor uses torque control.

[0040] The speed control of a three-phase permanent magnet synchronous motor includes an active flux observer to estimate the motor angle, a speed observer to observe the speed and load torque, and a torque PID loop and a current PID loop to control the motor speed and current in a dual-loop manner.

[0041] The expression for the active flux observer is:

[0042]

[0043]

[0044] ψ CM =K active ψ2|ψ2| -1 (3)

[0045] ψ VM =∫u-Ri+w v dt+L q i (4)

[0046]

[0047]

[0048] The expression for the rotational speed observer is:

[0049]

[0050]

[0051]

[0052]

[0053] Where: K active For active flux; L d It is a direct-axis inductor; L q For axial inductance; r req For virtual resistance; i d For stator direct-axis current; i q For stator quadrature-axis current; K E ψ1 is the stator flux linkage; u is the stator voltage; i is the stator current; wv For interference; k p k is the scaling factor for the flux linkage observer. i ψ is the integral coefficient; ψ2 is the active flux vector; ψ CM For the current model, the corresponding magnetic flux linkage is ψ. VM For the magnetic flux corresponding to the voltage model; Quadrature axis current estimate; n is the estimated motor speed. pp J represents the number of pole pairs of the motor. s This refers to the moment of inertia of the motor. K is the estimated load torque value. p K is the proportional coefficient of the speed observer; i K is the integral coefficient; d These are the differential coefficients; ε is the quadrature-axis voltage; ε is the error operator;

[0054] The speed control method used in ammonia fuel engines involves taking the difference between the estimated engine speed and the given speed, and using the coolant temperature and speed error as inputs. The PID coefficients are determined by looking up tables in the proportional system MAP, integral coefficient, and derivative coefficient tables. After PID calculation, these coefficients are accumulated to obtain the speed-regulating ammonia injection quantity. The no-load ammonia injection quantity is obtained by looking up the table using the coolant temperature as input. The feedforward ammonia injection quantity is dynamically corrected by looking up the table using the converted estimated engine speed and torque as inputs. Finally, the speed-regulating ammonia injection quantity, the feedforward quantity, and the no-load ammonia injection quantity are accumulated to obtain the ammonia injection quantity required for the final controlled speed.

[0055] The conversion relationship between the estimated speed of the ammonia fuel engine and the estimated speed of the electric motor is as follows:

[0056]

[0057] Where: n e For ammonia fuel engine speed; θ e This refers to the crankshaft rotation angle; Estimate the angle of the motor rotor; T e For engine torque; η m For motor efficiency.

[0058] First, the three-phase currents of the three-phase permanent magnet synchronous motor and the given reference voltage are sampled and converted into the corresponding α and β axis currents and voltages in the Clark coordinate system. Using the α and β axis currents and the reference voltage as inputs, the estimated value of the motor rotor angle is calculated by the active flux linkage observer 9 using equations (1)-(6). Using the estimated value of the motor rotor angle as input, the stator current under the α and β axes is transformed by Park to obtain the stator current under the dq axis. Using the stator current under the dq axis as input and the given reference voltage under the dq axis as input, the estimated motor speed and the estimated value of the load torque are calculated by the speed observer 6 using equations (7)-(10). The difference between the estimated value of the load torque and the given torque is entered into the torque PID loop 7. The speed PID loop 7 outputs the reference dq axis current and the difference between the actual stator dq axis current fed back by the motor. After passing through the current PID loop 8, the given reference voltage under the α and β axes is output. Finally, the SVPWM waveform generation module 10 sends a signal to the inverter 11 to control the motor stator current to control the motor torque.

[0059] The estimated motor speed and estimated motor load torque obtained from motor control are converted into ammonia engine speed and load torque using equation (11). The ammonia engine speed and torque are used as inputs to query the dynamic correction table for feedforward ammonia injection quantity in Table 5 to obtain the feedforward value. The difference between the given engine speed and the engine speed calculated from the estimated motor speed is used. The no-load ammonia injection quantity is obtained by querying the no-load ammonia injection quantity MAP table using the coolant temperature and engine speed as inputs. The PID output is obtained by querying the PID proportional coefficient MAP1, integral coefficient MAP2, and derivative coefficient MAP3 using the coolant temperature and engine speed as inputs and performing PID calculations. Finally, the feedforward ammonia injection quantity, the PID output ammonia injection quantity, and the no-load ammonia injection quantity are summed, and the required ammonia injection quantity for the engine is output using a MIN / MAX strategy, thus completing the engine speed control.

[0060] The crankshaft angle signal required for other engine controls can be given by formula (11) and used to determine the top dead center, cylinder, and fuel injection timing.

Claims

1. A hybrid intelligent power generation collaborative control method based on a position sensorless motor control, characterized in that: The ammonia fuel engine and the three-phase permanent magnet synchronous motor are controlled by speed control and torque control respectively. The torque control of the three-phase permanent magnet synchronous motor includes an active flux linkage observer, a speed observer, a torque PID loop and a current PID loop. The expression of the active flux linkage observer is: ψ CM = K active ψ2|ψ2| -1 ψ VM = ∫u - Ri + w v dt + L q i The expression of the speed observer is: where: K active is the direct-axis inductance; L d is the direct-axis inductance; L q is the direct-axis inductance; r req is the virtual resistance; i d is the direct-axis stator current; i q is the quadrature-axis stator current; K E is the permanent magnet flux linkage; ψ1is the stator flux linkage; u is the stator voltage; i is the stator current; w v is the disturbance; k p is the flux observer proportional coefficient; k i is the integral coefficient; ψ2is the active flux linkage vector; ψ CM is the current model corresponding flux linkage; ψ VM is the voltage model corresponding flux linkage; is the motor rotor estimated angle; is the quadrature-axis current estimated value; is the motor speed estimated value; n pp is the motor pole pair number; J s is the motor moment of inertia; is the load torque estimated value; K p is the speed observer proportional coefficient; K i is the integral coefficient; K d is the differential coefficient; u' q is the quadrature-axis voltage; ε is the error operator; The ammonia fuel engine is controlled by speed control, and the difference between the estimated engine speed and the given speed is taken as the input, together with the cooling water temperature and the speed error, to determine the PID coefficients through proportional system MAP table lookup, integral coefficient table lookup and differential coefficient table lookup, and then the PID coefficients are accumulated to obtain the speed-adjusting ammonia injection amount after PID operation; the cooling water temperature is taken as the input to look up the no-load ammonia injection amount and obtain the no-load ammonia injection amount; the converted engine estimated speed and torque estimated value are taken as the input to look up the feed-forward ammonia injection amount dynamic correction and obtain the feed-forward amount; finally, the speed-adjusting ammonia injection amount, the feed-forward amount and the no-load ammonia injection amount are accumulated to obtain the final control ammonia injection amount required by the engine speed. The conversion relationship between the estimated speed of the ammonia fuel engine and the estimated speed of the motor is: wherein: n e is the engine speed, i.e. the converted engine speed estimate; θ e is the crank angle; T e is the engine torque, i.e. the converted engine torque estimate; η m is the motor efficiency.

2. The hybrid intelligent power generation collaborative control method based on sensorless motor control according to claim 1, characterized in that: The center line of the shaft corresponding to the wide tooth gap of the flywheel signal disc in the ammonia fuel engine is aligned with the stator winding A-phase space position axis of the three-phase permanent magnet synchronous motor, and the A-phase is aligned with the direct axis in the three-phase coordinate system and the direct-quadrature axis coordinate system; meanwhile, the crankshaft sensor of the ammonia fuel engine is cancelled.

Images