The car governor system hydraulic pressure device provides a steady pressure oil source to the governor. When the pressure is low, control the two oil pumps to start alternately. When the pressure is too low, start two oil pumps at the same time to ensure that the tank pressure in the normal range.
First, the general situation
The oil pressure device control system of a hydropower station auxiliary project is composed of one control panel, two start screens, two oil pressure pumps, two air supply devices, oil pressure oil level transmitter and other electrical equipment. The hydraulic pressure signal is mainly based on the analog value of the oil pressure transmitter and the auxiliary value of the switch. Then the GE Versa Max PLC program of the control panel controls the soft start of the startup screen to control the start and stop of the oil pump. In order to reduce the loss of mechanical and electrical equipment, it is necessary to run the valve several seconds before starting and stopping the pump. When the pressure is low, the program according to the number of start-up for the preparation of large, small-based, the main alternate; the default when the same number of 1-based, 2-based for the preparation. In the control screen, when PLC communicates with the touch screen in Kunlun state, the range of the oil pressure level, the alarm value of the oil pressure level and the start and stop value of the oil pressure can be read and written through the touch screen according to the requirements of the owner.
Two, debugging problems of car governor control systems
- When the oil pressure is low, when the two control modes are removed, the two control modes are cut to automatic, and the two sets are opened at the same time.
- The touch screen cannot read and write PLC registers.
- During the rotation start-up, it is found that the main and standby signals of the two oil pumps jump and cannot start or start at the same time.
In the case of manual automatic switching, the delay of one second added to the main and standby program of car governor control system can be judged as follows:
Fig. 1 Adding delay program diagram:
Kunlun Tong Tai Touch Screen communicates with PLC. In the device window/internal attributes of the touch screen, the data types of adding R registers are BCD code, binary and floating-point number. The different symbols and digits of these three data types, and the data types of GE Versa Max PLC are binary, octal, decimal and hexadecimal and text. Read and write normally after changing to binary data type.
Fig. 2 Inner channel of touch screen of the car governor system
Fig.3 PLC data type selection
When the pressure is low, the main and standby signals jump and cannot start or start at the same time, which is due to the inconsistency of the data types between the two pumps starting times R00300 and R00303, resulting in the program judgment of the main and standby confusion. The same is binary, octal, decimal, sixteen hexadecimal system.
Fig. 4 Times rotation comparison program
PLC program logic of governor control system is relatively simple, automatic control using analog as the main, switch as a supplement, increase the reliable letter of the program; touch screen can read and write the alarm value of PLC analog, transmitter range, valve running time, etc., increase the program can be modified; in the data should pay attention to the corresponding data types of the program. To avoid confusion in program execution.