1. Field of the Invention
The present invention relates to a compressor and an air-conditioner having the same and, more particularly, to a compressor capable of enhancing an operation efficiency in an area where an operational environment is abnormal and an air-conditioner having the air-conditioner.
2. Description of the Related Art
In general, a compressor is applied to an air-conditioner. Recently, as the functions of air-conditioners and the like are diversified, a compressor whose capacity can be changed is on demand. As a technique for varying the capacity of the compressor, a technique for controlling the number of rotations of the compressor by employing an inverter motor and a technique for mechanically controlling a vane to idly rotate it are widely known.
First, the technique employing the inverter motor has a problem in that because the inverter motor is costly, the burden of a unit cost is high, and it is difficult to increase a freezing capability in a cooling condition compared with an increase in a freezing capability in a heating condition.
Meanwhile, the technique for idly rotating the vane by mechanically controlling it includes two types of methods: The first is constraining and releasing the vane by varying the pressure of a refrigerant supplied to a compression space of a cylinder; and the second is constraining and releasing the vane while changing the pressure applied to a rear surface of the vane.
In the case of the compressor, in an area where a voltage situation is not good, a low voltage is frequently generated, and in this occurrence, motive power of the compressor is insufficient to stop the compressor. Namely, during a certain time domain during which power of the compressor is turned off, refrigerant is not compressed, failing to obtain a cooling effect to make it difficult to realize an agreeable cooling operation. If an ambient temperature is high, the compressor is stopped, so the refrigerating is not compressed during a certain time domain while power of the compressor is turned off, failing to obtain a cooling effect to make it difficult to realize an agreeable cooling operation. Because the compressor is repeatedly turned on and off, power consumption increases and the reliability is degraded.
In addition, when a discharge temperature of the compressor refrigerator is high, power of the compressor is cut off by an electric overload protection (OLP) device or a temperature sensor to thus protect the compressor. In addition, when an ambient temperature is high, the same operation is performed. In particular, in an area, such as a tropical region, in which an ambient temperature is considerably high, such operation is frequently performed. If such operation is frequently performed, the refrigerant is not compressed during a certain time domain, failing to obtain a cooling effect to make it difficult to realize an agreeable cooling operation. Also, because the compressor is repeatedly turned on and off, power consumption increases and the reliability is degraded.
In addition, with the excessively high ambient temperature, the compressor is continuously operated in a power mode, excessive cooling operation is performed even at night, failing to provide an agreeable cooling operation and causing big noise.