| 摘要 |
An energy recovery system 10 is disclosed. The energy recovery system 10 is for use with an electricity supply including a microgeneration supply 100 and a utility supply 104, and aim is to reduce export of energy to the utility supply 104 by diverting excess generated electricity to a resistive load, for example an immersion heater 114. The energy recovery system 10 includes power output modulating means for modulating the proportion of maximum power supplied at the power output. The power output modulating means cycles between a power-on state and a power-off state, the relative timing of the pulse width modulation being adjusted to control the duty cycle and therefore the average power supplied. The energy recovery system 10 further includes a power measurement module, which is adapted to read input from a current sensor 16 when the power output modulating means is in the power-off state and to read input from the current sensor 16 when the power output means is in the power-on state, and to derive the power supplied to the load 114 from the difference of those measurements. The current sensor 16 measures magnitude and direction of current flow to/from the utility supply 104, and no separate current sensor is provided for directly measuring the current supplied to the load 114. |
