1. Introduction AC motor servo drive systems have gradually become the foundation of modern industries due to their simple structure and ease of maintenance. AC servo systems are increasingly widely used in joint drives for robots and manipulators, as well as in precision CNC machine tools. AC servo systems consist of AC motors. The digital model of an AC motor is not a simple linear model but exhibits nonlinearity, time-varying characteristics, and coupling, making it difficult to effectively control using traditional object-model-based control methods. For the performance of AC servo systems, on the one hand, good fast tracking performance is required, meaning the system must respond quickly to input signals, have small tracking errors, short transition times, and little or no overshoot, with few oscillations. On the other hand, high steady-state accuracy is required, meaning the system has small steady-state errors and high positioning accuracy. In AC servo control, conventional control methods are generally based on PID control. However, simple PID control has disadvantages such as large overshoot, long settling time, and low control efficiency, and its parameters are relatively difficult to select. In ordinary PID control, the integral term is used to eliminate static errors and improve the control accuracy of the system. If an integral term is introduced in the initial stage when the error is large, it will cause integral accumulation in the PID, resulting in a large overshoot in the system. Therefore, this paper designs an integral separation control method based on the characteristics of PID control. When the system error is large, the integral term is eliminated to avoid large overshoot caused by integral accumulation; when the system error is small, the integral term is introduced to eliminate the error and improve control accuracy. This integral separation PID control is applied to the real-time position control of an AC servo system, resulting in relatively ideal static and dynamic performance indicators of the control process. 2 System Structure Design The structure of the integral separation PID control AC servo system is shown in Figure 1. In the figure, θd is the given angular displacement, θ is the actual angular displacement of the motor shaft, and e is the deviation obtained by comparing θd and θ. Then: In Figure 1, u is the desired speed value of the PID control; ωd is the desired motor speed; ω is the actual motor speed; the deviation between ωd and ω generates the desired motor electromagnetic torque Td through the speed regulator. Since the deficiency of the inner loop can be compensated by the outer loop control, a general PI regulator can be used for the speed regulator, while the electromagnetic torque control of the motor adopts the direct torque control method. 3. Integral Separation PID Controller PID control is a mature and widely used control method with a simple structure and good control effect for most processes. Its discrete PID control law is as follows: Where u(k) is the output of the controller at time k; KP, KI, and KD are the proportional coefficient, integral coefficient, and derivative coefficient, respectively; e(K) is the difference between the position of the AC servo system at the current time and the expected value; e(k-1) is the difference between the position of the AC servo system at the last sampling time and the expected value. From equation (2), the increment between the control quantity u(k) at the k-th cycle and the control quantity u(k-1) at the (k-1)-th cycle can be obtained as: In PID control, the role of the integral element is to eliminate static error and improve the control accuracy of the system. If the integral element is introduced in the initial stage with a large error, it will cause: the integral accumulation of PID, which will cause a large overshoot of the system. Therefore, this paper designs an integral separation control method based on the characteristics of PID control. The flowchart of the integral separation PID control algorithm is shown in Figure 2. When the system error is large, the integral term is eliminated and PD control is adopted to avoid large overshoot caused by integral accumulation; when the system error is small, the integral term is introduced and PID control is adopted to eliminate the error and improve the control accuracy. That is: Where ε>0 is a manually set threshold. The integral separation control algorithm can be expressed as: Where T is the sampling time and a is the switching coefficient of the integral term, that is: 4 Experimental Study The AC motor parameters used in the experiment are Pn=2.2 kW, Un=220 V, In=5 A, nn=1440 r/min, r1=2.91 Ω, r2=3.04 Ω, Is=0.456 94 H, Ir=0.456 94 H, Im=0.444 27 H, Ten=14 N.