Brief Analysis on Digital Generator Inverter Controller and Its System Throttle Control

Digital generators are a new generator product field developed in recent years. The popularization of this product is mainly concentrated in small generator systems below 5 kilowatts.
Traditional generator products mainly use low-speed engines to drive an industrial frequency output generator to work normally and directly output the corresponding required power. This type of system has a relatively large volume due to the low speed of the engine. At the same time, for the generator, the volume of the low-speed generator is also difficult to be reduced, and it is difficult to miniaturize and portability for the entire system.
In terms of the quality of the output power supply, since the voltage and frequency of the output power supply are proportional to the engine speed, the fluctuation of the system speed under different load conditions will directly affect the stability of the output power supply voltage and frequency. The waveform of the output power supply is directly affected by the generator. Generally, the TDH of the output waveform of this type of small-power generator is not very ideal. The emergence of digital generator solutions has solved the above problems very well.

Digital generator controller product description:

The controller product combines advanced power inverter technology with control technology. The output waveform is a standard sine wave. The specific waveform is as follows:

Software closed-loop control technology is used in the system power output. Compared with conventional hardware control methods, this product has a high utilization efficiency of the engine output power, so that the same engine system can have a higher system output utilization efficiency. Compared with the traditional generator system, the output waveform of this control system in the full power output stage is a sine wave, and the output power quality is high and the stability is good.
This system has a high degree of freedom in the type of output power supply, and can output power of different frequencies and voltages according to the specific requirements of different customers. The current output power types are as follows: 
A, 220V/50Hz standard sinusoidal voltage output; 
B, 230V/50Hz standard sinusoidal voltage output; 
C, 110V/60Hz standard sinusoidal voltage output; 
D, 115V/60Hz standard sinusoidal voltage output.

In terms of system control, we use advanced dynamic intelligent applicable control solutions. Due to the particularity of the system part of this product, if the engine system, carburetor part, and throttle adjustment mechanical part have a certain degree of discreteness, the traditional system control solution cannot accurately and stably achieve effective adjustment of the system under variable load conditions, or even if effective adjustment is achieved, it cannot achieve dynamic energy-saving effects during the adjustment process. Our system uses a control solution with our own technical characteristics, thus achieving effective and accurate control of the system. At the same time, our control system has strong system adaptability. In the development process of system control design, we use self-developed PC software to realize the development method of combining controller with PC monitoring and analysis.

 We use the powerful monitoring and analysis capabilities of PCs to dynamically monitor and analyze the system, thus ensuring that we can achieve high-quality development of system control in a relatively short period of time. Since all the core technologies of this product are independently developed by us and we have advanced development methods, we can ensure that we have a faster response speed and stronger adaptability in matching different customers of this product. We guarantee that within our series of products, we can cooperate to complete the development of a full-function prototype within four weeks, provided that the customer's system prototype is completed.

In terms of system adaptability, our controller system has a wide range of matching. In terms of matching the system, our controller can adapt to the oil engine system of high-speed power engines and medium and low-speed power engines. In the actual system, we make corresponding adjustments to the corresponding control parameters of the controller, so as to realize the matching ability of our controller to engine systems with different characteristics without making corresponding changes to the hardware.

In engine systems with different characteristics, our controller can achieve the same high-quality system control capability and power output quality. 
In terms of product functions, features and advantages, our overall functions are as follows: 
1. Standard sinusoidal voltage output function; 
2. Electronic throttle speed control function; 
3. Power usage status management and monitoring function; 
4. Perfect system abnormal adjustment and protection processing function; 
5. System output indication, abnormal indication (LED display) function; 
Our products try to use perfect software monitoring and processing in design, and try to use software design to replace hardware design as much as possible. Thereby greatly improving the design reliability of the system. In the processing of output waveforms, we use a waveform generation method controlled by pure software, so that there is a better processing solution for the reliability and flexibility of the output power supply. The direct inverter system dynamic compensation method is adopted, so that the system has a higher inverter efficiency, while improving the efficiency of engine output power utilization, greatly reducing the temperature rise of the controller system. Our unique power soft start function in the system power output stage ensures the impact current suppression capability of the whole system combined with our controller in the power output stage. At the same time, we have added our unique whole system flameout control function in the design of the controller in the event of an extreme abnormality of the whole system. In the event of an extreme abnormality in the system, the engine is forced to shut down to ensure the safety of the whole system. At the same time, our controller system has a built-in temperature detection function. In the event of an abnormal temperature inside the controller system, the control system can make appropriate processing to ensure the absolute safety of the whole system. Brief analysis of system throttle control:

There are several aspects that make up the digital generator inverter controller. Among these aspects, inverter control and system throttle control are its core parts. Now I will introduce some personal experience of the throttle control part. Because it involves some specific technologies, it is inconvenient to talk more. I can only make a simple introduction and communicate with you. The main purpose of throttle control is to achieve effective control of the engine output power and effective control of DC voltage during the dynamic working process of the system. There should be more means to achieve throttle control during the dynamic working process of the system based on different ideas.

From the perspective of automatic control, the control characteristics of the throttle control model should be a hysteresis system. At the same time, due to the relative changes in the characteristics of the machine processing consistency and long-term operation, the uncertainty of the hysteresis degree is caused, which ultimately increases the control difficulty of the system. In this system, a good throttle control scheme should have the following characteristics: 
1. Realize static stability control at different speeds; 
2. Realize effective and stable control of the sudden increase and decrease of the maximum rated load during the operation of the system; 
3. Realize stable control of the variable load process; 
4. Still be able to achieve effective control of the system after certain changes in the system state (such as the decrease in engine output power capacity, slight blockage in the carburetor, etc.); 
5. Realize fast and accurate handling of the throttle under abnormal conditions.

From the perspective of automatic control, we must conduct a specific analysis of the system before achieving effective control of a system. The first step is to analyze the input parameters and output parameters, and determine the mutual cause and effect relationship. In this system, in order to achieve throttle control, we can use the following input quantities: system speed, DC voltage, output current, and output power. Changes in speed lead to changes in DC voltage (assuming the output power is constant), and changes in output power will lead to changes in system speed (assuming the throttle is fixed). It can be seen that changes in load are the internal cause of large changes in the system (of course, the output current is also the corresponding manifestation of the load size). Therefore, in order to achieve the best effect, effective control of the system must take the system load change as an important parameter (of course, some other parameters are also indispensable). Regardless of whether you ultimately expect to stabilize a specified speed or a specified voltage, load change is a very important parameter.

Relative to the engine system, if we expect to dynamically stabilize the system speed, we take the system speed as a physical variable and the load as a physical variable, then we can think of the load as a mutable variable (relative to the system speed) and the system speed as a gradual variable. What is the benefit of this analysis? The benefit of this analysis is that during the system control process, in order to achieve rapid and effective control of the system speed, we can use the load to perform relative system feedforward control.

Of course, in order to achieve effective control of a system, the details must also be done well, and the local functional design cannot be separated from the larger system framework. For example, a good system throttle control must also make certain mutual coordination with the inverter part. For specific products, such as digital generator system throttle control, this product does not require high-precision control like servo systems and motion control systems. In the design of this system, after the initial control accuracy is achieved, the focus should be on the adaptability and stability of the control design.