| 摘要 |
PURPOSE:To always maintain a compressor motor in high efficiency state irrespective of the load variation by varying the value of V/f in response to a load. CONSTITUTION:Assume that a load current Ia of approx. high load flows when a compressor motor 3 is started. Then, the data D3 in a V/f data memory 8 is selected by a load amount discriminator 7. When becoming a normal load current Ib state, data D2 is selected. When becoming a light load state, i.e., a load current Ic state, data D1 is selected. When the data D3 is selected in an inverter 2, the V and (f) are controlled so that the value of V/f maintains a3. Similarly, when the data D2 is selected, it is controlled to maintain a2. When the data D1 is selected, it is controlled to maintain a1. In this manner, even if the load largely varies, the prescribed high efficiency can be maintained. |
