CN201994844U - Power supply with passive power factor correction network - Google Patents

Abstract

The utility model discloses a power supply with a passive power factor correction network, which comprises an input filter circuit 1, a passive power factor correction network 2 and an output conversion stage 3. The AC output of the output conversion stage 3 and the AC input of the power supply share N [NEUTRAL] lines, and the sine wave operates synchronously without an isolation transformer. The passive power factor correction network 2 is connected between the input filter circuit 1 and the output conversion stage 3 of the power supply, and has a passive power factor correction function and a passive boosting function. The above-mentioned one type of power supply with passive power factor correction network is simple, reliable, high in efficiency and low in cost.

Description

A Class of Power Supply with Passive Power Factor Correction Network

technical field

The utility model relates to the technical field of power supply, specifically a kind of power supply with a passive power factor correction network, which has a passive power factor correction function and allows the AC output and AC input of the power supply to share N [NEUTRAL] lines.

Background technique

Energy efficiency, environmental protection and cost have always been the three technical focuses in the power supply field. At present, in order to meet the requirements of power factor value, all kinds of power supplies are usually specially equipped with a first-level active power factor correction circuit to complete voltage boost and power factor correction, and because the output and input cannot share N [NEUTRAL] lines, it is necessary isolation transformer. These will undoubtedly reduce the efficiency of the whole machine and increase the cost of the whole machine. So people are always exploring the solutions to the above problems.

Utility model content

The utility model discloses a power supply with a passive power factor correction network, which completes the functions of passive power factor correction, bootstrap boost rectification or double voltage rectification, and allows the AC output and AC input of the power supply to share N [NEUTRAL] lines , eliminating the need for an isolation transformer. This provides necessary conditions for ensuring high efficiency, low cost, simple structure, miniaturization, and high input power factor of the whole machine.

The utility model adopts the following technical solutions to solve the above-mentioned technical problems:

The power input is transmitted to the passive power factor correction network 2 through the input filter circuit 1, and it is boosted and rectified to generate a unidirectional sine wave voltage with a DC component to supply the output conversion stage 3, wherein the DC component is the boosted part of the voltage , to meet the output voltage amplitude requirement of the output conversion stage 3, one of which a unidirectional sine wave voltage provides a passive power factor correction function, because in this period, the output conversion stage 3 directly from the power input H [HOT] Line, N[NEUTRAL] line absorb pulse current.

The passive power factor correction network 2 includes rectifier diodes Dr1 and Dr2, the negative pole of Dr1 is connected to the positive output terminal of the passive power factor correction network 2, the positive pole of Dr1 is connected to the negative pole of the diode Dr2 and the AC input N[NEUTRAL] line of the power supply On the node, the positive pole of Dr2 is connected to the negative output terminal of the passive power factor correction network 2.

The passive power factor correction network 2 also includes an upper energy storage network 21 and a lower energy storage network 21', the positive output terminal of the upper energy storage network 21 is connected to the positive output terminal of the passive power factor correction network 2, Its negative output terminal is connected to the positive output terminal of the lower energy storage network 21' and the H[HOT] line node of the mains input, and the negative output terminal of the lower energy storage network 21' is connected to the negative output of the passive power factor correction network 2 end.

The circuit forms and component parameters of the upper and lower energy storage networks 21 and 21' are identical, and the discharge voltage of the upper and lower energy storage networks 21 and 21' is determined by the circuit structure of the energy storage networks. After an excessive cycle, the discharge voltage can be N/M of the amplitude of the power input sine wave voltage, or one/N, where N is an integer, and M=N+1.

According to the required boost amplitude and the power factor value of power input, different circuit structures can be selected. Describe below in conjunction with accompanying drawing.

Description of drawings

Fig. 1 is a block diagram of a power supply with a passive power factor correction network of a class of the utility model;

Fig. 2 is a block diagram of an embodiment of the utility model for a UPS power supply without an isolation transformer.

Fig. 3 is a block diagram of an embodiment of the utility model for a switching power supply.

In the accompanying drawings, the list of parts represented by each label is as follows:

1 is the block diagram of the input filter circuit, 2 is the block diagram of the passive power factor correction network, 3 is the block diagram of the output conversion stage, 4 is the battery system block diagram of the UPS power supply, 21 is the upper energy storage network block diagram, 21' is the lower energy storage network block diagram, 21-2, 21-2' are respectively an implementation of the upper and lower energy storage networks, 21-3, 21-3' are respectively another implementation of the upper and lower energy storage networks, and 3-1 is UPS The block diagram of the half-bridge inverter of the power supply, 3-2 is the block diagram of the output stage of the half-bridge resonant switching power supply.

Detailed ways

The principles and features of the present utility model are described below in conjunction with the accompanying drawings, and the examples given are only used to explain the utility model, and are not used to limit the scope of the utility model.

As shown in Figure 1, a block diagram of a power supply with a passive power factor correction network;

The power input is transmitted to the passive power factor correction network 2 through the input filter circuit 1, and it is boosted and rectified to generate a section of unidirectional sinusoidal voltage with a DC component, which is supplied to the output conversion stage 3, and the DC component included is the voltage boost The voltage part is used to meet the output voltage amplitude requirements of the output conversion stage 3, which includes a section of unidirectional sine wave voltage, which provides a passive power factor correction function, because during this period, the output conversion stage 3 is directly input from the power supply H[HOT] line and N[NEUTRAL] line absorb pulse current, the length of this period determines the input power factor value of the power supply.

When the output of the power supply is allowed to be synchronized with the input sine wave voltage, the output of the output conversion stage 3 can share the N[NEUTRAL] line with the input of the power supply, and the isolation transformer is omitted.

Fig. 2 is the embodiment block diagram of the UPS power source that is used for the utility model without isolation transformer. Its characteristic is that the output of the UPS power source is synchronous with the power input sine wave voltage, and the output of the output transformation stage 3 and the power input are N[NEUTRAL ] line, eliminating the isolation transformer.

In Fig. 2, 21-2 is the upper energy storage network, and 21-2' is the lower energy storage network, which are respectively a first-level flow-by-flow circuit, which together with the rectifier diodes Dr1 and Dr2 complete the bootstrap boost rectification, and the bootstrap boost The amplitude increment is about half of the amplitude of the power input sine wave voltage. In an ideal situation, if the power input sine wave voltage amplitude is 300V, the voltage applied to the half-bridge inverter 3-1 of the UPS power supply includes a DC component of 150V and a unidirectional sine wave with a voltage amplitude of 300V, which is enough to invert The output voltage amplitude requirements of the inverter 3-1; in the case of a pure resistive load, the half-bridge inverter 3-1 is directly input from the power supply H [HOT] line and N [NEUTRAL] line absorb pulse current, so the input power factor of the power supply can be made very high.

Fig. 3 is a block diagram of an embodiment of the utility model for a switching power supply. In Fig. 3, the connection between the output end of the switching power supply and the N [NEUTRAL] line of the mains input is disconnected. In Fig. 2, 21-3 is the upper energy storage network, and 21 -3' is the lower energy storage network, the circuit forms and parameters of the two are exactly the same, each including N charging branches and M discharging branches composed of 2N energy storage capacitors and [2N+1] diodes, M =N+1, N is an integer.

Wherein, the positive pole of the energy storage capacitor C1, the positive pole of C3, ——, the positive pole of [C2N-1], the negative pole of the diode D[2N+1] are connected to the positive output pole of the upper energy storage network 21-3, and the energy storage capacitor The negative pole of C2, the negative pole of C4, ——, the negative pole of C[2N], the positive pole of diode D1 are connected to the negative output pole of the upper energy storage network 21-2; the negative pole of diode D1 is connected to the positive pole of diode D2 and the energy storage capacitor C1 The cathode node of the diode D2, the cathode of the diode D2 is connected to the anode of the diode D3 and the anode node of the energy storage capacitor C2, the cathode of the diode D3 is connected to the anode of the diode D4 and the cathode node of the energy storage capacitor C3, the cathode of the diode D4 is connected to the anode of the diode D5 and The anode node of the energy storage capacitor C4, --, the cathode of the diode D[2N-1] is connected to the anode of the diode D2N and the cathode node of the energy storage capacitor C[2N-1], and the cathode of the diode D2N is connected to the diode D[2N+1] ] and the positive node of the energy storage capacitor C2N.

After several transitional cycles after initial power-on, the ratio of the discharge voltage of the energy storage network to the amplitude of the input sine wave voltage is approximately N:M, where M=N+1, where N is an integer. For example, N=3, M=4, the discharge voltages of the upper and lower energy storage networks are each about 0.75 times the amplitude of the input sine wave voltage, so the voltage added to the output stage 3-2 of the half-bridge resonant switching power supply , whose DC component is about 1.5 times the amplitude voltage of the input sine wave. The amplitude of the AC component is about 0.25 times the amplitude of the input sine wave voltage, corresponding to the input voltage sine wave is about 48.6 degrees to 131.4 degrees, that is, within the period of 48.6 degrees to 131.4 degrees of the input voltage sine wave, the half-bridge resonance The output stage 3-2 of the type switching power supply directly draws the pulse current from the power supply input line, so the input power factor of the power supply can be made very high.

Claims (5)

1. the power supply of a class band reactive power factor correcting network is characterized in that:

Pass through input filter circuit (1) successively after the civil power input and carry out filtering, reactive power factor correcting network (2) carries out conversion, after export after output transform level (3) conversion.

2. the power supply of band reactive power factor correcting network according to claim 1, it is characterized in that: reactive power factor correcting network (2) comprises rectifier diode Dr1, Dr2, the negative pole of Dr1 connects the positive output end of reactive power factor correcting network (2), the negative pole that the positive pole of Dr1 meets diode Dr2 exchanges input N[NEUTRAL with power supply] on the node of line, the positive pole of Dr2 connects the negative output terminal of reactive power factor correcting network (2).

3. the power supply of band reactive power factor correcting network according to claim 1, it is characterized in that: described reactive power factor correcting network (2), also comprise identical energy storage network (21) and the following energy storage network (21 ') gone up of circuit form and parameter, the positive output end of the positive output termination reactive power factor correcting network (2) of last energy storage network (21), the H[HOT of the positive output end of energy storage network (21 ') and civil power input under its negative output termination] the line node, the negative output terminal of the negative output termination reactive power factor correcting network (2) of following energy storage network (21 ').

4. the power supply of band reactive power factor correcting network according to claim 1, it is characterized in that:, allow the interchange output of power supply to be total to N[NEUTRAL with the input that exchanges of power supply in the interchange output of power supply and exchanging under the sinusoidal wave synchronous condition of the voltage of importing of power supply] line.

5. the power supply of band reactive power factor correcting network according to claim 3, it is characterized in that: upper and lower energy storage network (21,21 '), can be respectively storage capacitor C1, a C1 ', the positive pole of storage capacitor C1, C1 ' connects the positive output end of upper and lower energy storage network (21,21 ') respectively, and the negative pole of storage capacitor C1, C1 ' connects the negative output terminal of upper and lower energy storage network (21,21 ') respectively.

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