## 1 Introduction  
The energy crisis has become a vital issue restricting the further development of human technology, and the saving of energy and green development have become new and essential concepts. The development of electrification in construction machinery has become a significant trend [1]. The traditional single pump corresponds to the hydraulic system of a multi-actuator excavator. Due to the load difference, the hydraulic system experiences profound throttle loss and overflow loss at the valve port. In hydraulic excavator arms, a variable-speed motor is employed to drive a pump-controlled hydraulic cylinder system, effectively mitigating throttle losses at the valve ports and significantly enhancing the system's overall energy efficiency [2]. The development of electrification makes feasible the distributed hydraulic system. From the structure of the excavator, the traveling motor is decoupled from the boom, bucket rod, bucket, and rotary mechanism so that each actuator can be controlled according to the volume-speed regulation mode, eliminating the throttling loss caused by the load difference of multiple actuators, and the closed hydraulic system effectively reduces the corresponding pipeline and fuel tank volume [3]. Given problems such as the low energy utilization rate and poor endurance caused by profound energy consumption loss and load-power mismatching in the hydraulic system of the existing electric-driven excavator, the pump-controlled hydraulic cylinder system scheme is adopted for the excavator motor arm, which can eliminate the throttle loss at the valve port from the system configuration and control the motor speed and hydraulic pump displacement. The real-time matching between the output power of the hydraulic drive unit and the demand power of the load can effectively reduce the power loss in the energy conversion process of the motor to the hydraulic pump [4]. The working condition of the boom changes frequently, and the mismatch between the output power and the load power of the hydraulic drive unit results in profound energy consumption loss. The analysis of dynamic energy consumption during the switching of the variable-speed pump-control system under working conditions is of great significance for improving the global power matching of the system and reducing energy consumption [5]. There have been many studies on the use of pump-control systems to drive excavator working devices; for example, [PERSON] analyzed the position and velocity characteristics of the pump-controlled differential cylinder system by using double pumps to control the hydraulic cylinder system to drive the 37t excavator arm. The results showed that compared with the single-pump-controlled differential cylinder, the position and velocity response characteristics of the modified double-pump-controlled differential cylinder were improved, the system ran more smoothly, and the accumulator had a significant energy storage effect. The output energy consumption was reduced by 40% and 44% under no-load and on-load conditions. However, the influence of load change on the system energy consumption was not considered [6]. [PERSON] et al. transformed the pump-controlled cylinder system for the excavator's working device and established simulation models for the traditional valve-control system and the pump-controlled cylinder system, respectively, for the working device. Through analysis and comparison, the energy consumption of the excavator using the servo motor pump-control cylinder under a typical cycle condition was about 65% less than that of the traditional valve-control system. However, the motor speed was not controlled for load changes to match the load with the power source [7]. [PERSON] designed a pump-controlled integrated hydraulic cylinder system for the excavator motor arm. The unique cavity hydraulic cylinder eliminated unbalanced flow and recovered and utilized the boom potential energy, and the system ran smoothly. The energy-saving effect was remarkable [8].