The composition of EPOS--V-type electronic power optimization system
The composition of EPOS-V electronic power optimization system is shown in Figure 15-30.
1, Ⅱ power mode
Daewoo excavator control system This model has 3 power modes, namely Ⅰ speed mode, Ⅱ speed mode, Ⅲ speed mode. The output power of the I-speed mode is about 68% of the maximum power, the II-speed mode is about 85%, and the III-speed mode is about 100%. When the engine is started, it is automatically set to the second speed mode. You can use the buttons on the dashboard to select various power modes. When you select a certain power, the button indicator lights. Set the flow rate and engine speed according to the selected mode.The output flow rate of the pump in each mode is based on the flow rate corresponding to the maximum engine speed. 1. III speed mode The hydraulic pump flow rate corresponding to various loads in the III speed mode is based on the engine's The power curve is determined to maximize the power of the engine. The EPOS-V controller compares the actual speed with the set speed to control the current of the electromagnetic proportional pressure reducing valve to change the output flow of the hydraulic pump.
When the load increases and the engine speed drops below the rated speed, the control unit detects this change and immediately reduces the output flow of the hydraulic pump to keep the engine at the rated speed. Conversely, when the load is reduced, the control unit increases the output flow of the hydraulic pump and also keeps the engine at rated speed.
Repeat the control in this way, the engine speed is about the rated speed, and the output power is the largest. In the Ⅲ speed mode, the control unit receives the signals from the engine speed sensor and the governor and turns them into current signals, which are sent to the electromagnetic proportional pressure reducing valve of the hydraulic pump. The electromagnetic proportional pressure reducing valve transmits the control pressure corresponding to this current to two hydraulic pumps to control the output flow of the hydraulic pump.
2. Ⅱ speed mode
II speed mode is used for general operations. If this mode is selected, compared with the Ⅲ speed mode, noise and fuel consumption will be reduced, and the current of the electromagnetic proportional pressure reducing valve that controls the flow rate will be cut off. When the engine throttle control knob is at the maximum position, the engine speed is 150/min less than the maximum speed
3. I speed mode
Ⅰ speed mode is used when fast operation is not required. If this mode is selected, the speed of the excavator will be reduced, which can improve the performance of detailed operations. Compared with the Ⅱ speed mode, it can reduce noise and save fuel. The current of the electromagnetic proportional pressure reducing valve that controls the flow is cut off, and when the engine throttle control knob is at the maximum position, the engine speed automatically drops to 80% of the maximum speed.
In three power modes, the power curves of the engine and hydraulic pump are shown in Figure 1531
4. Power mode
Control circuit diagram The power mode control circuit is shown in Figure 1532.
