What are the common parameters of electric actuators?
As an important Actuator in the industrial automation control system, the electric actuator can be controlled centrally from a long distance to meet the needs of computer program control. With ball valves, butterfly valves, regulating valves, globe valves, gate valves, it forms an electric control system, which can switch or adjust the flow of the pipeline.
Taking THEOBORN, which is often selected as a shortlisted brand by the bidding of electric valve projects, as an example, THEOBORN electric actuator is used to control 0°~270° rotation valves and other similar products, such as butterfly valves, ball valves, dampers, baffle valves, plug valves, louver valves, etc., which can be widely used in petroleum, chemical, water treatment, shipbuilding, papermaking, power station, heating, light industry and other industries. The ball valve with the THEOBORN electric actuator is called the electric ball valve, the butterfly valve with the THEOBORN electric actuator is called the Electric Butterfly Valve, and the regulating valve with the THEOBORN electric actuator is called the electric control valve.
Many project owners are optimistic about the performance parameters of THEOBORN Electric Actuators, what are the main parameters of your Electric Actuators, this article will conduct a detailed analysis
1. Basic error (accuracy)
This is an important parameter to evaluate the control accuracy of electric actuators (electric actuators). The formula is as follows:
Calculation formula for basic error of electric actuator (electric actuator)
where: δ —— basic error, %
The L0 output shaft travel conventions the true value, the linear unit is mm, the angular stroke unit is degrees, and the multiturn unit is R.
L1 outputs shaft travel measurements, linear units for MM, angle stroke units, and multi-rotation units for R
The L0 output shaft travel conventions the true value, the linear unit is mm, the angular stroke unit is degrees, and the multiturn unit is R.
Measurement Method:
Measurement method of proportional electric actuator (electric actuator) (i.e., adjustable): slowly increase or decrease the input signal, and record the output shaft trajectory value in the positive and negative directions, which is calculated according to the basic error calculation formula.
A method of measuring an integral electrical actuator ("electric actuator") (i.e., a type of switch with feedback): Slowly increasing or decreasing the position transmitter signal in a manual manner and recording the output shaft line values in both positive and negative directions. According to the basic error calculation formula, the maximum error is obtained when 0%, 25%, 50%, 75% and 100% are entered in the upper and lower directions and the two directions, respectively, and the maximum value is obtained when the input is 0%, 25%, 50%, 75% and 100% respectively.
2. Return
The return stroke difference is an indicator of the repeatability of an electric actuator (electric actuator). The measurement method is the basic error measured at different points in different directions (generally 25%, 50%, 75%, 100% on the upper line, 75%, 50%, 25%, 0% on the lower line), and the absolute value of the difference between the upward and downward errors at the same point. Back to the one with the biggest difference.
3. Dead zone
The dead zone is when the signal increases or decreases by one value, the electric actuator ("electric actuator") does not act, and the maximum value is the dead zone of the electric actuator ("electric actuator"), which measures 25%, 50%, 75%, 100% of the stroke. Slowly increase (or decrease) the input signal until one of the output shafts can observe the stroke change and note the current input value I1; The input signal is then slowly changed in the opposite direction until the output shaft action is observed, the current input value I2 is recorded, and the dead band value is calculated according to the following formula:
Dead Band Calculation Formula for Electric Actuators (Electric Actuators)
where: △ —— dead zone, %
I —— Input range
4. Output torque (thrust)
This is a very important parameter of an electric actuator (electric actuator) and is an indicator of its driving capacity, in the case of straight stroke electric actuators (electric actuators) this parameter is called maximum thrust in N or kg, 1 kg = 10N. For quarter-turn or multi-rotary electric actuators ("electric actuators"), this parameter is referred to as the maximum output torque in n. m or Kg.m, 1Kg.m = 10N.m. This parameter is measured by directly driving the load with an electric actuator (electric actuator) and measuring the maximum load it can drive.
5. Input signal
This is clearly indicated in the article "Methods and Techniques for Selection" of electric actuators.
6. Output signal
In the article, the selection method and technology of electric actuators are also more clearly explained.
The input and output signals of imported electric actuators of VTON generally use current signals 4-20Ma or voltage signals 0-10V
7. Protection level
That is, the enclosure protection level (IP code), which can refer to the national standard GB4208-93 enclosure protection level. The common ones are IP65, IP66, IP67