CN218387252U - Economical high-level energy-taking power supply - Google Patents

Abstract

The utility model relates to an economical high-order energy-taking power supply, which comprises a BUCK voltage-reducing circuit and a DC/DC switching power supply which are connected in sequence; the BUCK voltage reduction circuit comprises switch tubes Q1-Q3, diodes D1-D3, an inductor L1 and a capacitor C1, an input positive end of the high-level energy-taking power supply is sequentially connected with the switch tube Q1, the switch tube Q2, the switch tube Q3, the inductor L1 and the capacitor C1 in series and then connected with an input negative end of the high-level energy-taking power supply, the diodes D1-D3 are sequentially connected with one another in series in the same conduction direction to form a diode series branch, an anode of the diode series branch is connected with the input negative end, and a cathode of the diode series branch is connected with a contact between the switch tube Q3 and the inductor L1. The utility model discloses a power high efficiency, control are simple, the cost is lower.

Description

Economical high-level energy-taking power supply

Technical Field

The utility model belongs to the technical field of the power electronics and specifically relates to an energy power is got to economical high position.

Background

The high-order energy-taking power supply is a special power supply applied to a VSC-HVDC converter valve, the input voltage of the high-order energy-taking power supply is DC 300V-DC 4500V, the rated input voltage is DC2800V, the output voltage is DC16V, the power is 18W, and the efficiency is higher and better; the input and output electrical isolation insulation grade is 10kV, and the leakage current is less than 5mA; the input end has surge suppression capability, and the power supply continues to output normally when in surge.

The high-order energy-taking power supply has the characteristics of high input voltage, wide voltage range, high electrical isolation grade and the like. In the conventional practice in the market, a plurality of resistors are connected in series to divide voltage, and after a smaller voltage is divided across each resistor, a conventional switching power supply is connected in parallel across the resistors to obtain an output voltage and power, as shown in fig. 1. The high-order energy-taking power supply of the method has extremely low working efficiency, consumes most energy on the resistor, has large loss and cannot be widely used; and the power supply generates heat seriously due to large loss, and is easy to damage in a high-temperature environment.

In order to reduce the voltage at the input end without excessive loss of electric energy, a method of dividing voltage by serially connecting capacitors appears in the market, and the more capacitors are connected in series, the smaller the voltage on each capacitor is. After the capacitors obtain smaller voltage, the capacitors are connected in parallel with the conventional switching power supply, and finally the output ends of the switching power supplies are connected in parallel to output voltage and power, as shown in fig. 2. In the figure, the resistors R1-R3 connected in parallel on the capacitors C1-C3 are capacitor voltage-sharing resistors, the resistance is very large, and a small amount of electric energy is consumed. The high-order energy-taking power supply of the method has higher working efficiency, but is complex to control, the output power of each conventional switching power supply needs to be adjusted in real time, so that the input equivalent impedance of each switching power supply needs to be basically equal, if the impedance is unequal, the divided voltage with large impedance is very high, and the divided voltage with small impedance is very low. Only when the dynamic equivalent impedance of each switching power supply is equal during working, the voltages on the capacitors can be balanced and kept basically equal. If the output power of each switching power supply is unbalanced, the voltages on the capacitors C1-C3 are unequal, even the difference is large, the voltage on some capacitors is very high, the voltage on some capacitors is very low, and the capacitors and the switching power supplies in the capacitor loops with high voltage are damaged due to overvoltage. And the high-order energy-taking power supply of this mode needs many switching power supplies to connect in parallel, makes its cost higher, and the volume is great.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to design an efficient, control simple, the lower high-order energy-taking power of cost.

Therefore, the economical high-order energy-taking power supply comprises a BUCK voltage reduction circuit and a DC/DC switching power supply which are sequentially connected; the BUCK voltage reduction circuit comprises switching tubes Q1-Q3, diodes D1-D3, an inductor L1 and a capacitor C1, wherein an input positive end of a high-level energy taking power supply is sequentially connected with the switching tube Q1, the switching tube Q2, the switching tube Q3, the inductor L1 and the capacitor C1 in series and then connected to an input negative end of the high-level energy taking power supply, the diodes D1-D3 are sequentially connected in series in the same conduction direction to form a diode series branch, an anode of the diode series branch is connected with the input negative end, and a cathode of the diode series branch is connected with a contact between the switching tube Q3 and the inductor L1.

Further, the withstand voltage of each switching tube and each diode is at least 1700V or more.

Furthermore, the G pole of each switching tube is controlled by the same control signal V.

Further, the transformer comprises a transformer Tr3, the transformer Tr3 is provided with a primary winding and at least three secondary windings, each secondary winding of the transformer Tr3 is connected with a trigger load in parallel and is respectively connected to the G pole of each switching tube, one end of the primary winding of the transformer Tr3 is grounded, and a control signal V is input to the other end of the primary winding of the transformer Tr 3.

Further, the transformer comprises a resistor R21, a capacitor C21 and a diode D21, one end of a primary winding of the transformer T1 is connected to an input point of the control signal V after being sequentially connected with the capacitor C21 and the resistor R21 in series, the end is connected with an anode of the diode D21, and a cathode of the diode D21 is connected with a joint point between the resistor R21 and the capacitor C21.

Compared with the prior art, the utility model discloses following beneficial effect has:

1. the control is simple, the control circuit and the control mode are not different from those of the conventional power supply, one path of PWM signal of the conventional power supply directly drives one switching tube, and the invention drives three switching tubes simultaneously without adding control signals and changing the control mode.

2. The high-order energy-taking power supply has the advantages that the efficiency is high, the problem that the voltage resistance of devices is not enough or the purchase is difficult due to the fact that a plurality of conventional devices are connected in series is solved, the power supply efficiency is the same as the parallel efficiency of the capacitor series connection voltage division multi-switch power supply module, and the efficiency is high.

3. The cost is low because the conventional device is connected in series to form the BUCK voltage reduction circuit, the mode that the capacitor is connected in series with the multi-switch power supply module in parallel is not adopted, and the control mode is the control mode of the conventional switch power supply, so the cost is low.

Drawings

Fig. 1 is a topological structure diagram of a resistor voltage division + high-order energy-taking power supply of a conventional switching power supply.

Fig. 2 is a topological structure diagram of a capacitor voltage division + high-order energy-taking power supply of a conventional switching power supply.

Fig. 3 is the electrical topology of the economical high-level energy-taking power supply of the present invention.

Fig. 4 shows a switching tube trigger circuit and an electrical simulation model.

Fig. 5 is a trigger waveform diagram.

Detailed Description

The technical solution of the present invention will be further explained with reference to the accompanying drawings and specific embodiments.

As shown in fig. 3, the economical high-level energy-obtaining power supply of the present embodiment is composed of a BUCK step-down circuit and a DC/DC switching power supply, which are connected in sequence. The input voltage is stepped down and stabilized to DC100V by the BUCK circuit, and then is electrically isolated and stepped down to DC16V output by the DC/DC switching power supply.

The BUCK voltage reduction circuit is composed of switching tubes Q1-Q3, diodes D1-D3, an inductor L1 and a capacitor C1. The switching tube is a 1700V switching device, and in order to meet the high-voltage requirement of 4500V, 3 switching tubes are connected in series; the diode also adopts 1700V diodes, and three diodes are connected in series, so that the requirement of 4500V withstand voltage is met. Considering that a certain deviation exists in the voltage-sharing of the series connection of the devices, certain voltage allowance is reserved for the type selection of the switching tube and the diode. When the high-order energy-taking power supply is connected, the input positive end of the high-order energy-taking power supply is sequentially connected with the switch tube Q1, the switch tube Q2, the switch tube Q3, the inductor L1 and the capacitor C1 in series and then connected to the input negative end of the high-order energy-taking power supply, the diodes D1-D3 are sequentially connected in series in the same conduction direction to form a diode series branch, the anode of the diode series branch is connected with the input negative end, and the cathode of the diode series branch is connected with a contact point between the switch tube Q3 and the inductor L1.

In the using process, the control device sends PWM waves to control the Q1-Q3 switching tubes to be switched on and off simultaneously, and the control device stabilizes voltage (DC 100V) output by changing the duty ratio of the PWM waves.

The switching tubes Q1-Q3 of the BUCK voltage reduction circuit are simultaneously switched on and off, the G pole is controlled by the same control signal V, and a transformer with three winding outputs is adopted for control in order to realize isolation and simultaneous triggering, as shown in figure 4. The transformer Tr3 is provided with a primary winding and at least three secondary windings, each secondary winding of the transformer Tr3 is connected with a trigger load in parallel and is respectively connected to the G pole of each switching tube, one end of the primary winding of the transformer Tr3 is grounded, the other end of the primary winding of the transformer Tr3 is connected with an input point of a control signal V after being sequentially connected with a capacitor C21 and a resistor R21 in series, the anode of the diode D21 is connected to the end of the primary winding, and the cathode of the diode D21 is connected with a connection point between the resistor R21 and the capacitor C21.

The resistor R21 plays a role in current limiting, the capacitor C21 isolates a direct current component, otherwise the transformer is easily saturated magnetically, the transformer Tr3 plays a role in electrical isolation, and the resistors R2 to R4 are equivalent to trigger loads, and are set to 20k Ω here.

Fig. 5 is a diagram of trigger waveforms, the first waveform is a control signal, and the remaining three waveforms are secondary output driving waveforms of the transformer. It can be seen from the figure that the control signal and the drive signal for the secondary side of the transformer are simultaneously off and simultaneously on.

The scheme of the embodiment uses fewer switching tubes and diodes, and simultaneously, the requirement on the insulation voltage class of the primary side of the DC/DC switching power supply is much lower, so that the DC/DC switching power supply is more economical.

The above embodiments are merely some preferred embodiments of the present invention, and those skilled in the art can make various alternative modifications and combinations to the above embodiments based on the technical solution of the present invention and the related teachings of the above embodiments.

Claims (5)

1. The utility model provides an energy power is got to economic high position which characterized in that:

the BUCK circuit and the DC/DC switching power supply are sequentially connected;

the BUCK voltage reduction circuit comprises switch tubes Q1-Q3, diodes D1-D3, an inductor L1 and a capacitor C1, an input positive end of the high-level energy-taking power supply is sequentially connected with the switch tube Q1, the switch tube Q2, the switch tube Q3, the inductor L1 and the capacitor C1 in series and then connected with an input negative end of the high-level energy-taking power supply, the diodes D1-D3 are sequentially connected with one another in series in the same conduction direction to form a diode series branch, an anode of the diode series branch is connected with the input negative end, and a cathode of the diode series branch is connected with a contact between the switch tube Q3 and the inductor L1.

2. An economical high-level energy-taking power supply according to claim 1, characterized in that: the withstand voltage of each switching tube and each diode is at least 1700V or more.

3. An economical high-level energy-taking power supply according to claim 1, characterized in that: the G pole of each switching tube is controlled by the same control signal V.

4. An economical high-level energy-taking power supply according to claim 3, characterized in that: comprises a transformer Tr3, the transformer Tr3 is provided with a primary winding and at least three secondary windings, each secondary winding of the transformer Tr3 is connected with a trigger load in parallel, and are respectively connected to the G pole of each switching tube, one end of the primary winding of the transformer Tr3 is grounded, and the other end is inputted with a control signal V.

5. An economical high-level energy-taking power supply according to claim 4, characterized in that: the transformer T1 comprises a resistor R21, a capacitor C21 and a diode D21, wherein one end of a primary winding of the transformer T1 is connected with an input point of a control signal V after being sequentially connected with the capacitor C21 and the resistor R21 in series, the end is connected with an anode of the diode D21, and a cathode of the diode D21 is connected with a joint point between the resistor R21 and the capacitor C21.

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