Air conditioning device

An air conditioning device, comprising:

• rectification means for rectifying an AC voltage outputted from an AC power source;
• smoothing means for smoothing the rectified AC voltage prior to conversion into a DC voltage;
• DC voltage-AC voltage conversion means for converting, by chopping, the DC voltage from said smoothing means into an AC voltage, whose voltage and frequency vary;
• an active filter, formed between said rectification means and said smoothing means, for shaping an input current to be an approximate sine wave almost in phase with an input voltage;
• overvoltage detecting means for detecting if the output voltage from said active filter is an overvoltage of not less than a predetermined threshold overvoltage value;
• and
• overvoltage preventing means for shutting off said active filter upon detecting that an output voltage from said active filter is an overvoltage, while ignoring a result of detection of overvoltage of said overvoltage detection means for a predetermined time immediately after a turn-on time and a turn-off time of said DC voltage-AC voltage conversion means or for a predetermined time immediately after a turn-on time of said active filter.

An air conditioning device, comprising:

• rectification means for rectifying an AC voltage outputted from an AC power source;
• smoothing means for smoothing the rectified AC voltage prior to conversion into a DC voltage;
• DC voltage-Ac voltage conversion means for converting, by chopping, the DC voltage from said smoothing means into an AC voltage, whose voltage and frequency vary, to be applied to a power compressor;
• an active filters, formed between said rectification means and said smoothing means, for shaping an input current to be an approximate since wave almost in phase with an input voltage;
• and
• overvoltage preventing means for shutting off said active filter upon detecting that an output voltage from said active filter is an overvoltage in excess of a predetermined threshold, and for raising the predetermined threshold for a predetermined time when starting up said active filter or said power compressor.

An air conditioning device, comprising:

• rectification means for rectifying an AC voltage outputted from an AC power source;
• smoothing means for smoothing the rectified AC voltage prior to conversion into a DC voltage;
• DC voltage-AC voltage conversion means for converting, by chopping, the DC voltage from said smoothing means into an AC voltage, whose voltage and frequency vary, to be applied to a power compressor;
• an active filter, formed between said rectification means and said smoothing means, for shaping an input current to be an approximate sine wave almost in phase with an input voltage;
• overvoltage preventing means for stopping said active filter upon detecting that the output voltage from said active filter is an overvoltage of not less than a predetermined threshold value;
• active filter control means for controlling the active filter, and including output voltage detection means for detecting an output voltage from said active filter, and voltage difference detection means for outputting a difference between the output detected by said output voltage detection means and a reference voltage, wherein said active filter control means includes waveform rounding means for rounding off the output from said voltage difference detection means, said active filter control means controlling said active filter so as to maintain an output voltage therefrom when said power compressor starts activating, not to exceed the predetermined threshold value.

An air conditioning device comprising:

• rectification means for rectifying the rectified AC voltage prior to conversion into a DC voltage;
• DC voltage-AC voltage conversion means for converting, by chopping, the DC voltage from said smoothing means into an AC voltage, whose voltage and frequency vary;
• control means for controlling an output frequency from said DC voltage-AC voltage conversion means according to a load state of said power compressor and for lowering a changing rate of an operating frequency of said power compressor for a predetermined time immediately after starting an alteration and immediately before completing the alteration of the operating frequency;
• and
• an active filters, formed between said rectification means and said smoothing means, for shaping an input current to be an approximate sine wave almost in phase with an input voltage.

An air conditioning device, comprising:

• rectification means for rectifying an AC voltage outputted from an AC power source;
• smoothing means for smoothing the rectified AC voltage prior to conversion into a DC voltage;
• DC voltage-AC voltage conversion means for converting, by chopping, the DC voltage from said smoothing means into an AC voltage, whose voltage and frequency vary, to be applied to a power compressor;
• an active filter, formed between said rectification means and said smoothing means, for shaping an input current to be an approximate sine wave almost in phase with an input voltage;
• load detection means for always detecting a load state of said power compressor during operation;
• output voltage setting means for increasing an output voltage of said active filter based upon a difference between a load state detected by said load state detection means when said power compressor is driven under an increased load and when said power compressor is driven under a load prestored when stably activating said power compressor so as to maintain the number of rotations of the power compressor constant;
• and
• active filter control means for controlling said active filter based on the increased output voltage.

An air conditioning device, comprising:

• rectification means for rectifying an AC voltage outputted from an AC power source;
• smoothing means for smoothing the rectified AC voltage prior to conversion into a DC voltage;
• DC voltage-AC voltage conversion means for converting, by chopping, the DC voltage from said smoothing means into an AC voltage, whose voltage and frequency vary, to a power compressor;
• an active filters, formed between said rectification means and said smoothing means, for shaping an input current to be an approximate sine wave almost in phase with an input voltage, a ground potential thereof matching that of said DC voltage-AC voltage conversion means;
• active filter control means for controlling said active filter;
• and
• power supply means for supplying a driving power to said DC voltage-AC voltage conversion means through a power source output terminal, said power supply means also supplying a driving power to said active filter control means through another power source output terminal.

An air conditioning device, comprising:

• rectification means for rectifying an AC voltage outputted from an AC power source;
• smoothing means for smoothing the rectified AC voltage prior to conversion into a DC voltage;
• DC voltage-AC voltage conversion means for converting, by chopping, the DC voltage from said smoothing means into an AC voltage, whose voltage and frequency vary, to be applied to a power compressor;
• an active filter, formed between said rectification means and said smoothing means, said active filter including a choke coil whose inductance decreases as current flowing into the coil increases, said active filter shaping an input current to be an approximate sine wave almost in phase with an input voltage by adjusting a flow of current into said smoothing means through said choke coil by switching a switching element;
• and
• switching control means for varying a switching frequency of said switching element, according to at least one of the current flowing through said choke coil and an output frequency of said AC power source, such that the switching frequency is increased as the current flowing into the coil increases.

An air conditioning device, comprising:

• rectification means for rectifying an AC voltage outputted from an AC power source;
• smoothing means for smoothing the rectified AC voltage prior to conversion into a DC voltage;
• DC voltage-AC voltage conversion means for converting, by chopping, the DC voltage from said smoothing means into an AC voltages, whose voltage and frequency vary, to be applied to a power compressor;
• an active filters, formed between said rectification means and said smoothing means, for shaping an input current to be an approximate sine wave almost in phase with an input voltage;
• active filter control means for controlling said active filter;
• overvoltage detection means for detecting that an output voltage from said active filter is in excess of a predetermined threshold;
• and
• power supply stop means for stopping power to be supplied to said active filter control means when the output voltage from said active filter is in excess of the predetermined threshold.

An air conditioning device, comprising:

• rectification means for rectifying an AC voltage outputted from an AC power source;
• smoothing means for smoothing the rectified AC voltage prior to conversion into a DC voltage;
• DC voltage-AC voltage conversion means for converting, by chopping, the DC voltage from said smoothing means into an AC voltages, whose voltage and frequency vary, to be applied to a power compressor;
• an active filter, formed between said rectification means and said smoothing means, for shaping an input current to be an approximate sine wave almost in phase with an input voltage;
• output voltage detection means for detecting an output voltage from said active filter;
• error detection means for detecting a difference between the output voltage and a preset reference voltage;
• output control means for controlling the output voltage to be maintained constant based on the difference;
• and
• limiting means for limiting the difference between the output voltage and the reference voltage to be not more than a predetermined value when starting up said active filter.

An air conditioning device, comprising:

• rectification means for rectifying an AC voltage outputted from an AC power source;
• smoothing means for smoothing the rectified AC voltage prior to conversion into a DC voltage;
• DC voltage-AC voltage conversion means for converting, by chopping, the DC voltage from said smoothing means into an AC voltage, whose voltage and frequency vary, to be applied to a power compressor;
• an active filters, formed between said rectification means and said smoothing means, for shaping an input current to be an approximate sine wave almost in phase with an input voltage by adjusting a flow of current into said smoothing means by switching a switching element;
• zero cross detection means for detecting a zero cross point of the input voltage of said active filter;
• and
• activation means for starting up said active filter at a zero cross point of the input voltage.

An air conditioning device, comprising:

• rectification means for rectifying an AC voltage outputted from an AC power source;
• smoothing means for smoothing an AC voltage rectified by said rectification means to be converted into a DC voltage;
• a DC voltage-AC voltage conversion means for converting by chopping the DC voltage from said smoothing means into an AC voltage whose voltage and frequency vary to be applied to a power compressor;
• an active filter formed between said rectification means and said smoothing means, said active filter including a choke coil and shaping an input current to be an approximate sine wave almost in phase with an input voltage by adjusting a flow of current into said smoothing means through said choke coil by switching a switching element;
• and
• inductance alternation means for increasing an inductance of said choke coil for a predetermined time after starting up said active filter.

An air conditioning device, comprising:

• rectification means for rectifying an AC voltage outputted from an AC power source;
• smoothing means for smoothing the rectified AC voltage prior to conversion into a DC voltage;
• DC voltage-AC voltage conversion means for converting, by chopping, the DC voltage from said smoothing means into an AC voltage, whose voltage and frequency vary, to be applied to a power compressor;
• an active filters, formed between said rectification means and said smoothing means and including, a choke coil for shaping an input current to be an approximate sine wave almost in phase with an input voltage by adjusting a flow of current into said smoothing means through said choke coil by switching a switching element;
• and
• inductance incrementing means for increasing an inductance of said choke coil for a predetermined time after starting up said active filter.

An air conditioning device, comprising:

• rectification means for rectifying an AC voltage outputted from an AC power source;
• smoothing means for smoothing the rectified AC voltage prior to conversion into a DC voltage;
• DC voltage-AC voltage conversion means for converting, by chopping, the DC voltage from said smoothing means into an AC voltage, whose voltage and frequency vary, to be applied to a power compressor;
• an active filter, formed between said rectification means and said smoothing means, for shaping an input current to be an approximate sine wave almost in phase with an input voltage and for boosting an input voltage based on a boost ratio;
• AC voltage detection means for detecting an AC voltage of said AC power source;
• voltage rise setting means for setting the boost ratio according to the AC voltage of said AC power source;
• and
• active filter control means for controlling the output voltage from the active filter based on the set boost ratio.

An air conditioning device, comprising:

• rectification means for rectifying an AC voltage outputted from an AC power source;
• smoothing means for smoothing the rectified AC voltage prior to conversion into a DC voltage;
• DC voltage-AC voltage conversion means for converting, by chopping, the DC voltage from said smoothing means into an AC voltage, whose voltage and frequency vary, to be applied to a power compressor;
• an active filter, formed between said rectification means and said smoothing means, for shaping an input current to be an approximate sine wave almost in phase with an input voltage by adjusting a flow of current into said smoothing means by switching a switching element;
• input voltage detection means for detecting an input voltage to said active filter;
• waveform generation means for generating an approximate sine wave according to a phase angle of the input current of aid active filter;
• phase synchronization means for making the approximate sine wave in phase with the input voltage of said active filter;
• and
• switching control means for controlling a switching of said switching element based on the approximate sine wave in phase with the input voltage.