4/23/2021 0 Comments Carlo Gavazzi Pdi 408 Pdf Bus
Dividing by cyclesPerSecond 50 gives the energy gained or lost during that individual mains cycle, in Joules.This system has proved to be both effective and reliable, and I am most grateful for everyone who has helped me along the way.
The main downside to this arrangement is that it requires an expensive item of third-party kit to distribute the power. I know that others have found cheaper ways, but my Carlo Gavazzi unit cost me 70). By using a zero-crossing detector such as the Motorola MOC3041, it should be possible for the Arduino to allocate mains cycles directly to the load rather than delegating this task to a separate device. Carlo Gavazzi Pdi 408 Bus Code To BeThis allows the code to be put through its paces without requiring any additional hardware just the Arduino. When running in this mode, voltage and current samples are synthesized, as is the operation of the triac. To convert it to normal mode, just comment out the define DEBUG statement. Surplus energy, as measured at the supply point, is recorded in this variable, and power is only allocated to the immersion heater when the available energy has reached a pre-determined level. The energy bucket is updated after each complete cycle of the mains, and a decision is then taken as to whether the triac should be on or off during the next cycle. If sufficient energy is not available, the triac will be off from the next zero-crossing point, just 10mS after that information has been gained. By updating the LPF only once per mains cycle (my idea), its performance is nigh-on perfect, with no attenuation or phase shift. There is also a standard HP filter which acts just on the voltage stream. The purpose of this secondary filter is to group the voltage samples into cycles so that the LPF can be accurately updated. Unlike the LPF, the HPF can always be relied upon to start up correctly. The LM358 runs from the Arduinos 5V rail and provides a rock-steady reference point. If separate reference circuits were to be used, the single LPF approach would then not be appropriate. This is because any DC offset in the current samples is removed by the maths. For other calculations such as Power Factor or Irms, the dc-offset of each sensor must be dealt with independently. To ensure that a small amount of export to the grid is maintained, a programmable safety margin has been included; this acts as a leak in the bucket thereby reducing the rate that on cycles can be allocated to the immersion. For anyone with a nervous disposition, just increase the value of safetyMarginwatts. Because there is only one place where current is measured (flowing into and out from the grid), any inaccuracy will be cancelled out. Once the distribution algorithm has reached the operating point, on cycles will be allocated at the appropriate rate for the prevailing conditions regardless of any absolute error in the measurement system (it just needs to be linear). By adding a mains cycles worth of instP values together, and dividing by the number of samples, this gives the average power during that mains cycle, also in Watts.
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