A power feed-forward-based diesel generator set speed regulation control method

Abstract

This invention provides a diesel generator set speed control method based on power feedforward, characterized by the following steps: Step M1: The generator set controller reads the current speed N and rated speed n of the diesel generator set from the speed sensor; reads the current active power P of the pulse load. t The active power P at the previous sampling time t' The current active power P t and the calculated power differential signal P e The signal is transmitted to the feedforward controller; Step M2: Calculate the feedback control signal; Step M3: Calculate the feedforward control signal Y. a Step M4: Feedback control signal and feedforward control signal Y a A voltage signal is generated by superimposing these signals using a specific algorithm and output to the electronic speed governor. This changes the oil supply, thereby altering the engine speed and bringing the power and speed deviations close to zero. This invention enables generator sets to achieve high-precision and rapid response to fast-dynamic loads such as pulse loads, and improves system stability.

Description

Technical Field

[0001] This invention relates to the field of generator set control technology, and more specifically, to a diesel generator set speed control method based on power feedforward. Background Technology

[0002] Diesel generator sets are the power source for most mobile power stations. Compared to mains power, their electrical energy inertia is smaller, and rapidly changing loads can easily cause significant fluctuations in the generator voltage and frequency, making power quality crucial. With technological advancements, high-power pulse loads, such as phased-array radars and laser weapons, are playing an increasingly important role in power systems. These loads exhibit high-frequency pulse characteristics, with lower average power and higher peak power, hence the term "pulse load."

[0003] In large-capacity mains power systems, the system inertia is strong, and sudden changes in pulse loads do not cause significant disturbances in grid voltage and frequency. However, in smaller-capacity mobile power stations, grid inertia is low, generator control and regulation time is long, and highly dynamic pulse loads can cause significant disturbances to the generator's output characteristics. Sudden load changes lead to large fluctuations in output current, disrupting torque balance and causing speed fluctuations and voltage distortions. This not only affects the normal operation of the equipment but may also damage the generator or the load over long-term use. Therefore, how to solve the speed fluctuations caused by pulse loads and achieve rapid power generation and response has become an urgent technical problem to be solved. Summary of the Invention

[0004] The purpose of this invention is to overcome the speed fluctuation of generator sets caused by pulse loads, and to provide a diesel generator set control system device based on power feedforward, which, combined with dynamically limited output voltage, improves response speed, reduces errors, and improves accuracy.

[0005] The technical solution of this invention is as follows: A speed control method for a diesel generator set based on power feedforward is characterized by the following components: a generator set controller, a diesel generator set, an electronic speed governor, a speed sensor, and a pulse load. The generator set controller includes a main control module, which has a speed controller and a feedforward controller. It includes the following steps: Step M1: The generator set controller reads the current speed N and rated speed n of the diesel generator set from the speed sensor and sends them to the speed controller to obtain the speed deviation signal e; the generator set controller reads the current active power P of the pulse load. t The active power P at the previous sampling time t' The current active power P t and the calculated power differential signal P e Transmitted to the feedforward controller; Step M2: The speed controller calculates the feedback control signal based on the speed deviation signal e using a traditional PID algorithm. ; Step M3: The feedforward controller determines the current active power P of the load. t and power differential signal P e The feedforward control signal Y is calculated using a pre-established feedforward control algorithm. a ; Step M4: Feedback control signal With feedforward control signal Y a A voltage signal is generated by superimposing the signals through a certain algorithm and then output to the electronic speed governor. The electronic speed governor controls the output throttle according to the obtained voltage signal, changes the fuel intake and thus changes the speed, thereby making the power deviation and speed deviation approach 0.

[0006] The beneficial effects of this invention are: This invention addresses the problem of speed oscillation and energy loss caused by rapid changes in pulse load power by introducing active power feedforward control, which improves the speed regulation speed.

[0007] This invention achieves both power regulation accuracy and pulse power response regulation speed requirements through power feedforward fuzzy control.

[0008] When the generator is closed, the feedforward control output is 0 to avoid the current surge during closing affecting the power quality of multiple units in parallel operation and to ensure synchronization of multiple units. After closing, the feedforward control output returns to the normal level at an exponential rate, with characteristics similar to a switch, exhibiting continuous characteristics, which can ensure both closing speed and rapid load response.

[0009] The fuzzy inference rule of this invention can effectively determine whether the load power is in an abnormal state. If an abnormal state is detected, the circuit breaker will be tripped and an alarm will be triggered, effectively protecting the load and generator set and preventing situations such as reverse power. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the speed control system structure of the present invention; Figure 2 This is a schematic flowchart of the power feedforward speed control method of the present invention; Figure 3 This is a schematic diagram of the fuzzy inference rules of the present invention. Detailed Implementation

[0011] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0012] like Figure 1As shown, the components used in the power feedforward-based diesel generator set speed control method of the present invention include: a generator set controller, a diesel generator set, an electronic speed governor, a speed sensor, and a pulse load; the generator set controller is used to collect and read parameters such as voltage, current, power, and frequency at the generator end and the bus end, and to run a control program to send signals to the electronic speed governor to reduce speed fluctuations; the diesel generator set is used to convert diesel kinetic energy into electrical energy to supply the pulse load; the electronic speed governor is connected to the generator set throttle, and changes the throttle opening degree by adjusting the input voltage, thereby changing the speed and power; the speed sensor is used to sensitively measure the speed signal of the diesel generator set and provide it to the generator set controller.

[0013] In one embodiment, a generator set controller is used, comprising a main control module, an energy acquisition module for obtaining parameters such as voltage and power, an analog output module for controlling the electronic speed governor, an analog input module for acquiring sensor data such as speed sensors, and a power supply module and a storage module for assisting algorithm execution. The generator set used is a diesel generator set without an ECU, and the electronic speed governor is used for speed regulation. The rated power is 200kW, the rated speed is 1500r / min, the rated output voltage is 400V AC three-phase, the flywheel has 112 teeth, and the speed governor voltage range is -5V to 5V. The main control module has a speed controller and a feedforward controller.

[0014] like Figure 2 As shown, the diesel generator set speed control method based on power feedforward of the present invention includes the following steps: Step M1: The generator set controller reads the current speed N and rated speed n of the diesel generator set from the speed sensor and sends them to the speed controller to obtain the speed deviation signal e; the generator set controller reads the current active power P of the pulse load. t The active power P at the previous sampling time t' The current active power P t and the calculated power differential signal P e Transmitted to the feedforward controller; In one embodiment, step M1 includes: Step M1.1: Read the current generator speed N from the speed sensor; Step M1.2: Pre-configure the rated speed n of the generator set; in this embodiment, n=1500. Step M1.3: Generate the rotational speed deviation signal e, e = n - N; Step M1.4: Read the current active power P at the pulse load terminal from the energy measurement module of the unit controller. t The active power P at the previous sampling time t' ; Step M1.5: Generate the power differential signal P e P e = P t -P t' .

[0015] Step M2: The speed controller calculates the feedback control signal based on the speed deviation signal e using a traditional PID algorithm. ; In one embodiment, step M2 includes: Step M2.1: The speed deviation signal e generated in step 1.3 generates a feedback control signal according to the PID control method. :

[0016] In the formula: This is the proportionality coefficient. The integral coefficient is... The differential coefficients are... This refers to the runtime; after parameter adjustment and optimization, the parameters selected in this embodiment are... , , .

[0017] Step M3: The feedforward controller determines the current active power P of the load. t and power differential signal P e The feedforward control signal Y is calculated using a pre-established feedforward control algorithm. a ; In one embodiment, step M3 includes: Step M3.1: The current active power P formed in step 1.4 t The power differential signal P formed in step 1.5 e According to a certain fuzzy control algorithm, the initial feedforward control signal Y is generated. s ; In one embodiment, step M3.1 includes: Input the current active power P t and power differential signal P e And the output value feedforward control initial signal Y s Establish quantization rules and membership functions, and then perform fuzzification; Step M3.1.1: Set the current active power P t The values ​​are divided into three language values: Big B, Medium M, and Small S. The rated power of the unit is quantized, and a membership function is selected, that is, the rated power is quantized from the range [0,200] to the range [0,1]. In this embodiment, a Gaussian membership function is used. Step M3.1.2: Convert the power differential signal P e The values ​​are divided into seven language values: negative large NB, negative medium NM, negative small NS, zero Z, positive small PS, positive medium PM, and positive large PB. The values ​​are quantized with reference to the rated power of the unit. The membership function is selected, that is, the power deviation is quantized from the range [-200, 200] to the range [-1, 1]. In this embodiment, a Gaussian membership function is used. Step M3.1.3: Input the initial feedforward control signal Y s The values ​​are divided into nine language values: negative large, negative medium, negative small, negative micro, zero, positive micro, positive small, positive medium, and positive large. The input voltage of the electronic speed controller is referenced for quantization, and a membership function is selected to quantize the output signal from the range [-5,5] to the range [-1,1]. In this embodiment, a triangular membership function is used. Step M3.1.4: Infer the fuzzy input into a fuzzy output U according to certain fuzzy rules. (Fuzzy rules are referenced below.) Figure 3 ; In the output rules, F represents an abnormal state. For example, if the power is small (S) and the power difference is negative (NB), this is clearly an abnormal situation. If the membership degree of state F exceeds a certain value, an alarm signal will be output. The control algorithm will directly output the center voltage and send an alarm signal to the external circuit breaker, causing the closing relay to trip. In this embodiment, when the sum of the membership degrees of state F is greater than 0.5, the control algorithm will directly output the center voltage and send an alarm signal to the external circuit breaker, causing the closing relay to trip and protecting the load and generator set. Step M3.1.5: Calculate the actual feedforward control initial signal Y from the output value of the fuzzy inference using the centroid method. s And convert it into the range of the actual output signal [-5,5] according to the quantization factor.

[0018] Step M3.2: The feedforward control output is 0 when the generator set is first started. To ensure signal continuity, an initial time attenuation is added to the initial feedforward control signal to form the feedforward control signal Y. a ;

[0019] In the formula, t is the generator set running time, and the generator set tripping time is set to time 0; l is the time coefficient, which is taken as a fixed constant. In this example, l = 0.5.

[0020] Step M4: Feedback control signal With feedforward control signal Y a A voltage signal is generated by superimposing the signals through a certain algorithm and then output to the electronic speed governor. The electronic speed governor controls the output throttle according to the obtained voltage signal, changes the fuel intake and thus changes the speed, thereby making the power deviation and speed deviation approach 0.

[0021] In one embodiment, step M4 includes: Step M4.1: The initial control voltage signal U0 of the electronic speed controller is determined by the feedback control signal Y. f and feedforward control signal Y a The two are combined to form: U0 = Y f + Y a Step M4.2: The range of the output feedforward control signal is the voltage input range of the electronic speed controller. To prevent the signals from the feedforward controller and the feedback controller from exceeding the limit after superposition, a limiting element is added to the initial control voltage signal to obtain the actual output voltage signal. :

[0022] In the formula, Un and Um are the lower and upper limits of the input voltage range of the electronic speed controller, respectively. They are usually constants and will change according to the needs of the speed controller. In this embodiment, Un = -5 and Um = 5, respectively. Step M4.3: The electronic speed governor adjusts the throttle according to the voltage signal, so that the speed error and power deviation tend to be 0, and has a good pulse load following effect.

[0023] In summary, this invention discloses a composite speed control method for diesel generator sets with power feedforward. Based on the active power and power differential signals obtained from the power measurement process, fuzzy calculations are performed, and then combined with speed PID feedback control to obtain the voltage output of the electronic speed governor. Compared to direct feedback control, this method offers faster adjustment speed and better response to pulse loads. Furthermore, by incorporating fuzzy judgment of abnormal power and initial attenuation of feedforward control, it achieves the identification of anomalies such as reverse power and improves the synchronization speed accuracy of parallel operation. Through this method, this invention enables generator sets to achieve high-precision and rapid response to fast dynamic loads such as pulse loads, and improves system stability.

[0024] It should be noted that the above description is merely illustrative and explanatory of the present invention. Those skilled in the art should understand that any modifications and substitutions to the present invention fall within the scope of protection of the present invention.

Claims

1. A speed control method for diesel generator sets based on power feedforward, characterized in that, The components used include: a generator set controller, a diesel generator set, an electronic speed governor, a speed sensor, and a pulse load. The generator set controller includes a main control module, which has a speed controller and a feedforward controller. It includes the following steps: Step M1: The generator set controller reads the current speed N and rated speed n of the diesel generator set from the speed sensor and sends them to the speed controller to obtain the speed deviation signal e; The unit controller reads the current active power P of the pulse load. t The active power P at the previous sampling time t' The current active power P t and the calculated power differential signal P e Transmitted to the feedforward controller; Step M2: The speed controller calculates the feedback control signal based on the speed deviation signal e using a traditional PID algorithm. ; Step M3: The feedforward controller determines the current active power P of the load. t and power differential signal P e The feedforward control signal Y is calculated using a pre-established feedforward control algorithm. a ; Step M4: Feedback control signal With feedforward control signal Y a A voltage signal is generated by superimposing the signals through a certain algorithm and then output to the electronic speed governor. The electronic speed governor controls the output throttle according to the obtained voltage signal, changes the fuel intake and thus changes the speed, thereby making the power deviation and speed deviation approach 0.

2. The diesel generator set speed control method based on power feedforward according to claim 1, characterized in that, Step M1 includes: Step M1.1: Read the current generator speed N from the speed sensor; Step M1.2: Pre-configure the rated speed n of the generator set; in this embodiment, n=1500. Step M1.3: Generate the rotational speed deviation signal e, e = n - N; Step M1.4: Read the current active power P at the pulse load terminal from the energy measurement module of the unit controller. t The active power P at the previous sampling time t' ; Step M1.5: Generate the power differential signal P e P e = P t -P t' .

3. The diesel generator set speed control method based on power feedforward according to claim 1, characterized in that, Step M2 includes: Step M2.1: Generate a feedback control signal from the speed deviation signal e using the PID control method. : ； In the formula: This is the proportionality coefficient. The integral coefficient is... The differential coefficients are... This refers to the runtime.

4. The diesel generator set speed control method based on power feedforward according to claim 1, characterized in that, Step M3 includes: Step M3.1: From the current active power P t and power differential signal P e According to a certain fuzzy control algorithm, the initial feedforward control signal Y is generated. s ; Step M3.2: The feedforward control output is 0 when the generator set is first started. In order to ensure signal continuity, an initial time attenuation is added to the initial feedforward control signal to form the feedforward control signal Y.

5. The diesel generator set speed control method based on power feedforward according to claim 4, characterized in that, Step M3.1 includes: Input the current active power P t and power differential signal P e And the output value feedforward control initial signal Y s Establish quantization rules and membership functions, and then perform fuzzification; Step M3.1.1: Set the current active power P t The values ​​are divided into three language values: large B, medium M, and small S. They are quantified with reference to the rated power of the unit, and a membership function is selected. Step M3.1.2: Convert the power differential signal P e The values ​​are divided into seven language values: negative large NB, negative medium NM, negative small NS, zero Z, positive small PS, positive medium PM, and positive large PB. The values ​​are quantified with reference to the rated power of the unit, and a membership function is selected. Step M3.1.3: Input the initial feedforward control signal Y s The values ​​are divided into nine language values: negative large, negative medium, negative small, negative micro, zero, positive micro, positive small, positive medium, and positive large. The values ​​are quantized with reference to the input voltage of the electronic speed controller, and a membership function is selected. Step M3.1.4: Infer the fuzzy input into a fuzzy output U according to certain fuzzy rules; In the output rules, F represents an abnormal state. If the membership degree of state F is greater than a certain value, an alarm signal will be output. The control algorithm will directly output the center voltage and send an alarm signal to the outside, and the closing relay will trip. Step M3.1.5: Calculate the actual feedforward control initial signal Y from the output value of the fuzzy inference using the centroid method. s .

6. The diesel generator set speed control method based on power feedforward according to claim 4, characterized in that, In step M3.2, the following formula is used for calculation: ； In the formula, t is the generator set running time, and the generator set tripping time is set to time 0; l is the time coefficient, which is taken as a fixed constant.

7. The diesel generator set speed control method based on power feedforward according to claim 1, characterized in that, Step M4 includes: Step M4.1: The initial control voltage signal U0 of the electronic speed controller is determined by the feedback control signal Y. f and feedforward control signal Y a The two are combined to form: U0 = Y f + Y a Step M4.2: The range of the output feedforward control signal is the voltage input range of the electronic speed controller. To prevent the signals from the feedforward controller and the feedback controller from exceeding the limit after superposition, a limiting element is added to the initial control voltage signal to obtain the actual output voltage signal. ; Step M4.3: The electronic speed governor adjusts the throttle according to the voltage signal, so that the speed error and power deviation tend to be 0, and has a good pulse load following effect.

8. The diesel generator set speed control method based on power feedforward according to claim 7, characterized in that, In step M4.2, the following formula is used for calculation: ； In the formula, Un and Um are the lower and upper limits of the input voltage range of the electronic speed controller, respectively.

9. The diesel generator set speed control method based on power feedforward according to claim 1, characterized in that, The generator set controller is used to collect and read parameters and run control programs to send signals to the electronic speed governor to reduce speed fluctuations; the diesel generator set is used to convert diesel motor energy into electrical energy; the electronic speed governor is connected to the generator set throttle and changes the throttle opening degree by adjusting the input voltage, thereby changing the speed and power; the speed sensor is used to sensitively measure the speed signal of the diesel generator set and provide it to the generator set controller.

10. The diesel generator set speed control method based on power feedforward according to claim 1, characterized in that, The unit controller further includes an energy acquisition module for acquiring parameters such as voltage and power, an analog output module for controlling the electronic speed governor, an analog input module for acquiring sensor data, and a power supply module and a storage module for assisting algorithm execution.

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