TWI722008B - A box formed by a frequency conversion air-conditioning protector with electromagnetic pulse protection function - Google Patents

Abstract

The present invention relates to a frequency conversion air conditioner with electromagnetic pulse protection function dedicated to the communication compartment. In addition to the electromagnetic pulse protection function and electromagnetic pulse interference suppression device of the power terminal, the frequency conversion air conditioner also has different indoor and outdoor functions. The electromagnetic pulse protection device at the power supply end is preferably provided with a conductive material for electromagnetic isolation at the cold air refrigerant pipeline passing through the cabin.

Description

A box formed by a frequency conversion air-conditioning protector with electromagnetic pulse protection function

An electromagnetic pulse interference suppression (EMI) air conditioner for vehicle compartments for communication. Military cabinets are generally equipped with electromagnetic pulse (EMP) protection devices for the main power supply. However, for the current energy-saving, environmentally friendly, and highly efficient inverter air conditioners, the current Generally, a power filter protection circuit with a low cut-off frequency will make it unable to work. This case discloses a high cut-off frequency electromagnetic pulse filter protection circuit variable frequency air-conditioning protector and the box formed by it. The characteristic of the box is that the box has electromagnetic pulse protection function and electromagnetic pulse interference suppression function.

Traditional communication boxes, including satellite communication, information management, or command vehicle communication boxes, mostly use conventional air-conditioning, except for the main power supply with a conjugate power filter device (as shown in the figure) 2), its cut-off frequency is usually below 30KHz.

The present invention discloses a malicious electromagnetic interference IEMI (INTENTIONAL ELECTRO-MAGNETIC INTERFERENCE) prevention box for communication. In addition to the EMP (ELECTRO-MAGNETIC PLUSE) electromagnetic pulse protection device that is generally provided with a power supply, it also contains at least a frequency conversion The filter device and protection device of the inverter, the filter cut-off frequency of the inverter is at least above 30KHz.

New-type communication cabinets, whether they are military or government cabinets, are gradually requiring energy saving and environmental protection; therefore, the air-conditioning used in such a cabinet must be Traditional air-conditioning becomes frequency-conversion air-conditioning; at the same time, for special purposes and safety considerations, it must also have the function of electromagnetic protection. Because the inverter air conditioner has a set of power lines and control lines between its indoor unit and outdoor unit, its transmission content is not a general 60Hz power supply, so it is necessary to design a special filter, usually the cut-off frequency of this filter, Do not use a conjugate filter like the previous power supply (filter above 1KHz). This will filter out the frequency conversion signal in the control line of the frequency conversion air conditioner, and the frequency conversion air conditioner may not operate normally, even if it can avoid strong operation. It is also impossible to achieve full load, and it is necessary to redesign the filter differently from the general one. In addition to the filtering function, an electromagnetic pulse suppression circuit with fast response (nanosecond level), high current (kiloamp level), and wide pulse wave (level above 0.5 microsecond) is required. This circuit is different from the existing static electricity prevention and control circuit. (ESD) or lightning (LIGHTNING) protection circuit.

11.31: Frequency conversion electromagnetic pulse protection filter with higher cut-off frequency

51: current limiting element

Figure 1. A schematic diagram of a power supply electromagnetic pulse protection filter with a low cut-off frequency and a high cut-off frequency electromagnetic pulse to absorb and protect the air-conditioning cabinet.

Figure 2. The basic architecture of a traditional low-cut-off frequency power supply conjugate filter.

Figure 3. An electromagnetic pulse protection filter circuit diagram of a frequency conversion signal between a frequency conversion air conditioner outdoor unit and an indoor unit or a frequency conversion power supply.

Figure 4. The module diagram of the electromagnetic pulse protection filter circuit disclosed in this case.

Fig. 5: The module diagram of the electromagnetic pulse protection filter circuit with better anti-lock function disclosed in this case.

Figure 6. The compartment disclosed in this case, in which the electromagnetic wave or electromagnetic pulse shielding of the refrigerant tube is blocked.

This case discloses a high cut-off frequency power supply protection air conditioner 11 with electromagnetic pulse (EMP) protection function; and a power supply filter protector with a low cut-off frequency at the same time, and a high cut-off frequency frequency conversion protection air-conditioning cabinet, as shown in the figure 1 shown. Its characteristic is that this box has electromagnetic pulse protection function and electromagnetic pulse interference suppression function. At least this box has two components at the same time. One is the electromagnetic pulse protection component of the power supply. The frequency of the power supply protection component's initial filtering is less than 30KHz; In addition, it is a fast-response electromagnetic pulse protection component for variable frequency air conditioner; and its variable frequency air conditioner has the function of pulse overvoltage protection, and its filter start frequency in the frequency domain should be greater than 30KHz.

As shown in Figure 2, this is a basic structure diagram of a traditional low-cut-off frequency power filter. It has a filter composed of resistors and capacitors at the inlet end, and a three-phase conjugate coil composed of a conjugate ring body in the middle. Later, there is a ground filter capacitor at the outlet port. The configuration described in this way is usually a low-pass circuit. Because the frequency of the power supply itself is 60Hz, it will filter out all the noise above 30KHz. Therefore, this The design is reasonable.

As shown in Figure 3, what we want to design is a frequency conversion signal between a frequency conversion air conditioner outdoor unit and an indoor unit or an electromagnetic pulse absorption and filtering protection circuit of a frequency conversion power supply. A unit such as 31, due to the signal inside, Generally, the frequency converter used now, because its switching element is a silicon-based element, such as MOSFET or IGBT, the frequency is between 100K~300K, and the withstand voltage is not high; in the past two years, there has been a wide band gap gallium nitride (GAN) or Silicon Carbide (SIC) and other components are developing rapidly, and it is expected to move towards higher operating frequencies (above 100MHz) in the future. But as shown in Figure 2, we use a traditional filter. In the first aspect, it does not have the function of electromagnetic pulse absorption. In the second aspect, the frequency that it filters out is too low, which will filter out the variable frequency signal, thus causing outdoor The machine will not work.

In order to solve the aforementioned problems, as shown in Figure 4, the filter circuit used in this air conditioner is a ring-shaped conjugate coil (as shown in Figure 2) is first changed to a simple inductance, and there is no coupling between the lines. Correlation, of course, can also be three-wire type or two-wire type, depending on the actual AC frequency conversion or DC frequency conversion or other situations. However, the key point is that its conjugate coils are changed to individual independent coils; secondly In order to increase the absorption of electromagnetic pulses, at least one zinc oxide (MOV metal oxide) or gas discharge tube (GDT) protection element should be provided in the large transient current discharge part at the front end, and the back of the independent coil is to filter out relatively small The residual signal can be increased by more than one level of over-voltage protection components, such as over-voltage clamp (TVS) or Zener diode (ZENER DIODE). Among them, different from the communication filter, the current endurance of the coil needs to be greater than 3 amperes, because the current is very small when the compressor is reloaded, but the current can reach 7 amperes or more under full load, depending on the model of course. However, the voltage may be as high as 240VAC. Of course, impedance matching may be considered. It is possible to install low-resistance resistors before and after the inductor, so I won't repeat it.

In addition to the general requirements, for the military regulations (MIL-STD) higher specification pulse current injection requirements, as shown in Figure 5, in front of the general zinc oxide protection element (MOV), gas is added at the same time Discharge tube (GDT) and other circuits.

However, the gas discharge tube has a disadvantage, that is, when it is activated by pulse intrusion, under 110VAC or 240VAC, it may latch up and continue to conduct current to the ground terminal. So that the system cannot work. In order to prevent this phenomenon, we can install a current-limiting element 51 above or below the gas discharge tube. Of course, this current-limiting element can be used as a fuse with a very small impedance, or directly use a self-recoverable resistor. The fuse, that is, it can be disconnected by itself, and will recover after the temperature drops The fuse to prevent the phenomenon of latch up (latch up).

Similar events, such as the over-voltage clamp (TVS) or Zener diode (ZENER DIODE) in Figure 4 or Figure 5, may be short-circuited under high current. To prevent this phenomenon, we can set it up or down A similar current-limiting component, of course, this current-limiting component can be used as a fuse with a very low impedance resistance, or it can be directly used as a fuse that can be self-recovered, that is, it can be disconnected by itself, and then after the temperature drops. Restore the fuse to prevent the occurrence of short circuit.

With the aforementioned absorption protection circuit, it is installed on the position of 31 in Figure 3, so that the special frequency conversion air conditioner for the cabinet has the function of pulse electromagnetic pulse absorption and noise filtering. For communication-related cabinets, It has the effect of preventing and controlling malicious electromagnetic pulse attacks. Of course, because the scope disclosed in this case is limited to communication-related boxes with inverter air-conditioning, there must be air-conditioning refrigerant pipes entering and leaving the box. In order to prevent condensation and dew, the refrigerant pipe will have an insulating sleeve on it. However, when the insulating sleeve enters and exits the box or the cabin, the copper or aluminum refrigerant pipe becomes a parasitic antenna, which is easy Cause the leakage of electromagnetic waves. Therefore, it is best to install an electromagnetic shielding conductive cotton, conductive yarn, conductive mesh, etc., or electromagnetic shielding metal braid, or other materials on the outer layer of the refrigerant insulation sleeve. Any conductive braid can further shield the electromagnetic wave or electromagnetic pulse of the car body disclosed in this case, as shown in Figure 6.

In summary, after the aforementioned protection, such boxes and compartments can achieve the effectiveness of electromagnetic shielding and electromagnetic pulse electromagnetic pulse absorption, which can improve our ability to prevent hard killings in electronic warfare and make a certain contribution to national defense independence.

11 : Frequency conversion electromagnetic pulse absorption filter with higher cut-off frequency

Claims (1)

A box body formed by a frequency conversion air-conditioning protector with electromagnetic pulse protection function, wherein the box body has at least three parts: more than one AC power supply; and the power supply has a cut-off frequency below 1KHZ conjugate power supply electromagnetic pulse protection filter It is placed on the box to facilitate the power signal to pass through the box without obstruction; and, more than one inverter air conditioner, and the inverter electromagnetic pulse protection filter with a cut-off frequency of 30KHz or more is placed on the box to facilitate frequency conversion The line passes through the box without obstruction; the variable frequency electromagnetic pulse protection filter has an independent inductance filter element, and at least one or more metal oxide varistors or absorption elements such as a gas discharge tube before the filter element; after the filter element , There is at least one overvoltage protection element or Zener element; and, the outside of the heat insulation sleeve of the variable frequency air-conditioning refrigerant passes through the box, and it is better to have a layer of conductive material for electromagnetic wave isolation to isolate electromagnetic waves.

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