Patent Description:
As a technology of integrating three networks (a telecommunications network, a cable television network, and the Internet) emerges, a mobile band, MBB, becomes increasingly broader, which causes that a power of a Radio Remote Unit, RRU, increases doubly, and a diameter of a cable becomes increasingly thicker because the power increases. In addition, for a relatively remote outdoor tower station, an outdoor roof station, or a relatively large-coverage indoor place, an RRU needs to have a remote capability, and in this case, a diameter of an RRU cable becomes relatively thick, so that costs of an RRU solution are increased, for example, an RRU remote terminal becomes larger, outgoing cables of a cabinet and a power distribution box are thicker, space needs to be increased, and an extra switching component is required, which are not beneficial to normalized design of a product.

In the prior art, a voltage boosting circuit for direct voltage boosting is disclosed. In the circuit, a voltage source is connected to a converter directly, and after the voltage source is converted by the converter, a required voltage is output.

However, by using the foregoing voltage boosting circuit, without considering a voltage value of an original voltage source, all powers of the voltage source pass through a whole converter directly, which easily causes low efficiency and high power consumption of a whole voltage boosting circuit in a process of boosting a voltage, and further brings a heat dissipation problem to a system that includes a voltage boosting circuit, so that the volume of the system is increased and costs of the system are increased.

<CIT> discusses a current supply system comprising a battery providing a source voltage, a switching unit which implements a turn on-off process in order to produce a pulsed current of the source voltage, an insulating transformer increasing, in response to the pulsed current, the source voltage to a increased or transformed voltage higher than the source voltage, a capacitor for buffering the increased or transformed voltage and to provide increased or transformed voltage to a sensitive electrical device and a control unit, which controls the switching unit in such a way that the increased or transformed voltage coincides with a nominal voltage.

<CIT> discusses a power supply comprising a switching circuit, a transformer and a rectifier/smoothing circuit wherein the output voltage is coupled with the input voltage so that addition or subtraction may be performed. An input DC voltage is converted to an AC voltage via a switching circuit, the AC voltage is transformed via an insulated transformer and rectified via a rectifier/smoothing circuit. The output voltage of the rectifier/smoothing circuit is coupled so that another output voltage is obtained as a result of addition or subtraction to the input voltage.

<CIT> discusses a power generating system configured to provide direct current (DC) power to a DC link. The system includes a first power generation unit configured to output DC power. The system also includes a first DC to DC converter comprising an input section and an output section. The output section of the first DC to DC converter is coupled in series with the first power generation unit. The first DC to DC converter is configured to process a first portion of the DC power output by the first power generation unit and to provide an unprocessed second portion of the DC power output of the first power generation unit to the output section.

<CIT> discusses a voltage compensation system for photovoltaic modules including a photovoltaic module biasing means connected in series with a series string of photovoltaic modules. The biasing means may be a DC-DC converter. It is operable to generate a controllable bias voltage for modulating an output voltage of the photovoltaic modules to produce the compensated voltage output. A maximum power point (MPP) tracking algorithm may control the DC-DC converter. The voltage at the output terminals remains largely constant under the control of an inverter. Each string therefore operates at an optimum do voltage according to string conditions to improve efficiency.

Embodiments of the present invention provide a voltage regulating circuit, so as to solve a problem of low efficiency and high power consumption of a voltage boosting circuit in the prior art.

A first aspect of the present invention provides a voltage regulating circuit, including:.

It can be known from the foregoing technical solution that, the voltage regulating circuit in the embodiment of the present invention outputs a second voltage signal by using a voltage boosting unit, and a sum of the second voltage signal and a first voltage signal forms an output signal of the voltage regulating circuit. In this way, efficiency of voltage boosting in the voltage regulating circuit in the embodiment of the present invention can be improved, and power consumption of the voltage regulating circuit can be reduced, thereby reducing heat of a system in which the voltage regulating circuit is used and reducing the volume of the system.

To describe the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings required for describing the embodiments. Apparently, the accompanying drawings in the following description show merely some embodiments of the present invention, and persons of ordinary skill in the art may still derive other drawings from these accompanying drawings without creative efforts.

To make the objectives, technical solutions, and advantages of the present invention clearer, the following clearly and completely describes the technical solutions of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the following described embodiments are merely a part of the embodiments of the present invention. Based on the following described embodiments of the present invention, persons of ordinary skill in the art can obtain other embodiments which can solve the technical problem of the present invention and implement the technical effect of the present invention by equivalently altering a part of or all the technical features even without creative efforts.

<FIG> is a schematic structural diagram of a voltage regulating circuit according to an embodiment of the present invention. As shown in <FIG>, a voltage regulating circuit <NUM> in this embodiment includes: a main loop unit <NUM>, a voltage boosting unit <NUM>, and a switching control unit <NUM>, where.

In this embodiment, the voltage boosting unit <NUM> and the main loop unit <NUM> are disposed in parallel, and they share one voltage source <NUM>, that is, an input end of the main loop unit <NUM> is connected to the voltage source <NUM>, an input end of the voltage boosting unit <NUM> is connected to the voltage source <NUM>, and output ends of the main loop unit <NUM> (a and b shown in <FIG>) and output ends of the voltage boosting unit <NUM> (c and d shown in <FIG>) are connected in series to form output ends of the voltage regulating circuit <NUM> (a and d shown in <FIG>).

Particularly, in this embodiment, a short-circuit switch <NUM> is disposed between the output ends c and d of the voltage boosting unit <NUM>, where the short-circuit switch <NUM> is connected to the switching control unit <NUM>, so that the switching control unit <NUM> controls, when it is determined that the first voltage signal Us' is greater than or equal to the first reference voltage Vg, the short-circuit switch <NUM> to be closed, to enable a second voltage signal ΔU output by the voltage boosting unit <NUM> to be zero.

Specifically, an input end of the switching control unit <NUM> is connected to the output ends a and b of the main loop unit <NUM>, receives the first voltage signal Us' output by the main loop unit <NUM>, and the switching control unit <NUM> compares the first voltage signal Us' with the preset first reference voltage Vg; and if the first voltage signal Us' is less than the first reference voltage Vg, the short-circuit switch <NUM> is controlled to be opened by the switching control unit <NUM>, so that the voltage boosting unit <NUM> outputs a second voltage signal ΔU that is not zero; and if the first voltage signal Us' is greater than or equal to the first reference voltage Vg, the short-circuit switch <NUM> is controlled to be closed by the switching control unit <NUM>, that is, the output ends of the voltage boosting unit <NUM> are short-circuited, to enable the second voltage signal ΔU output by the voltage boosting unit <NUM> to be zero.

It should be noted that the preset first reference voltage Vg is usually <NUM>. 5V, which is a basic voltage used by an existing voltage class.

For example, the voltage boosting unit in this embodiment may be a full-bridge converter (as shown in <FIG>), a half-bridge converter (as shown in <FIG>), a push-pull converter (as shown in <FIG>), a forward converter (not shown in the figure) or a flyback converter (not shown in the figure), where an input end of the push-pull converter is connected to the voltage source, and is configured to convert the input signal Us of the voltage source into a required second voltage signal ΔU according to the input signal Us of the voltage source.

In an actual application, the voltage regulating circuit <NUM> further includes a feedback control unit (as shown in <FIG>), configured to regulate, according to the output signal of the voltage regulating circuit <NUM>, the second voltage signal ΔU output by the voltage boosting unit <NUM>.

In other words, the feedback control unit is configured to receive the output signal Vout of the voltage regulating circuit <NUM>, and regulate, according to the output signal Vout of the voltage regulating circuit, the second voltage signal ΔU output by the voltage boosting unit <NUM>. In this embodiment, a voltage value and/or a pulse width of the second voltage signal ΔU is regulated according to a voltage value and/or a pulse width of the output signal Vout, to enable the second voltage signal output by the voltage boosting unit <NUM> to be more stable.

It can be known from the foregoing embodiment that, the voltage regulating circuit in the embodiment of the present invention outputs a second voltage signal by using a voltage boosting unit, and a sum of the second voltage signal and a first voltage signal forms an output signal of the voltage regulating circuit. In this way, efficiency of voltage boosting in the voltage regulating circuit in this embodiment can be improved, and power consumption of the voltage regulating circuit can be reduced, thereby reducing heat of a system in which the voltage regulating circuit is used and reducing the volume of the system.

<FIG> is a schematic structural diagram of a voltage regulating circuit according to another embodiment of the present invention. As shown in <FIG>, the voltage regulating circuit in this embodiment is a specific circuit structure.

In this embodiment, output ends a and b of a main loop unit output a first voltage signal Us' whose voltage value is equal to a voltage value of a voltage source <NUM>.

A voltage boosting unit in this embodiment is a half-bridge converter <NUM>, as shown in a circuit diagram in a dotted box in the figure. In an actual application, the half-bridge converter <NUM> includes a rectifying unit inside, an input end of the half-bridge converter <NUM> is connected to the voltage source <NUM>, and output ends c and d of the half-bridge converter <NUM> are configured to output a second voltage signal ΔU that is obtained after conversion.

It should be noted that, in this embodiment, a half-bridge converter is used as a voltage boosting unit. A transformer in the half-bridge converter shown in <FIG> primarily uses a half-bridge circuit and secondly uses a full-wave rectifier, and preferably, the full-wave rectifier may be a full-wave diode rectifier.

Certainly, a short-circuit switch <NUM> is disposed between the output ends c and d of the half-bridge converter, and closing and opening of the short-circuit switch <NUM> are controlled by using a relay <NUM> in a switching control unit <NUM>.

In this embodiment, an output signal of the voltage regulating circuit is a sum of the first voltage signal Us' and the second voltage signal ΔU. In an actual circuit, output ends a and b of a main loop unit and output ends c and d of a voltage boosting unit may be connected in series, to enable output ends a and d of a voltage regulating circuit to output Us'+ΔU. In this embodiment, the voltage source is enabled to output, by using the voltage regulating circuit, a voltage signal that meets a requirement of a device.

The voltage regulating circuit in this embodiment is used as an example for description. Assuming that a required power of the voltage regulating circuit is 1000W and a required voltage of the voltage regulating circuit is 51V, in this case, a current is 1000W/<NUM> V=<NUM>.

When a voltage of the voltage source is Us=38V, the voltage boosting unit needs to output a second voltage signal ΔU=51V-38V=13V. In addition, a power output by the voltage boosting unit is 13V*<NUM>.

Assuming that the conversion efficiency of a voltage boosting unit outputting 255W is <NUM>%, an equivalent efficiency of a voltage regulating circuit outputting 1000W is: <NUM>-[<NUM>(<NUM>-<NUM>%)/<NUM>]=<NUM>. Therefore, the overall conversion efficiency of the voltage regulating circuit in this embodiment is improved effectively, and compared with that in the prior art, power consumption of the voltage boosting unit herein is quite low.

Further, in an actual application, it is relatively easy to set a voltage boosting unit of 255W.

In addition, it can be seen from <FIG> that, the switching control unit <NUM> in this embodiment mainly includes: a first sampler <NUM>, a first voltage comparator <NUM>, a diode, a triode <NUM>, and a relay <NUM>.

The first voltage comparator <NUM> is configured to compare a voltage value with a first reference voltage, where the voltage value is sampled by the first sampler <NUM> and output by the main loop unit; and when the voltage value sampled by the first sampler is greater than or equal to the first reference voltage, the first voltage comparator <NUM> outputs a high level, then the diode that is connected to a base of the triode <NUM> outputs the high level to the base of the triode <NUM>, to enable a collector of the triode <NUM> to output a signal, and then the relay <NUM> that is connected to the collector of the triode controls a short-circuit switch to be closed, to ensure that a voltage value of a second voltage signal output by an output end of the voltage boosting unit is zero.

Certainly, an input end of the first sampler <NUM> is connected to the output ends a and b of the main loop unit, and an output end of the first sampler <NUM> is connected to a first input end of the first voltage comparator <NUM>.

A second input end of the first voltage comparator <NUM> receives a given first reference voltage Vg, an output end of the first voltage comparator <NUM> is connected to an anode of the diode, a cathode of the diode is connected to the base of the triode <NUM>, an emitter of the triode <NUM> is connected to the ground, and the collector is connected to the relay <NUM> that controls the short-circuit switch <NUM> of the voltage boosting unit.

In other words, the first voltage comparator <NUM> receives a voltage value of the first voltage signal, where the voltage value of the first voltage signal is sampled by the first sampler <NUM> and output by the main loop unit, and compares the voltage value with the given first reference voltage Vg; and when the voltage value of the first voltage signal is greater than or equal to the first reference voltage Vg, the first voltage comparator <NUM> outputs a high level, and outputs the high level to the base of the triode <NUM> by using the diode that is connected to the output end of the first voltage comparator, and then controls, by using the relay <NUM> that is connected to the collector of the triode, the short-circuit switch <NUM> to be closed, to enable the output ends c and d of the voltage boosting unit to be short-circuited, where in this case, ΔU output by an output end of the voltage boosting unit is zero.

Certainly, in another embodiment, the switching control unit <NUM> may also use another hardware circuit to control opening and closing of the short-circuit switch of the voltage boosting unit, and the switching control unit <NUM> of this embodiment is only used as an example for description.

It can be known from the foregoing embodiment that, the voltage regulating circuit in this embodiment uses a half-bridge converter to output a second voltage signal, and the second voltage signal and a first voltage signal are connected in series to form an output signal of the voltage regulating circuit. In this way, efficiency of voltage boosting in the voltage regulating circuit in this embodiment can be improved, and power consumption of the voltage regulating circuit can be reduced, thereby reducing heat of a system in which the voltage regulating circuit is used and reducing the volume of the system.

<FIG> is a schematic structural diagram of a voltage regulating circuit according to another embodiment of the present invention, and <FIG> is a schematic structural diagram of a feedback control unit in a voltage regulating circuit according to another embodiment of the present invention. As shown in <FIG>, a difference between a topology of a voltage regulating circuit shown in <FIG> and a topology of a voltage regulating circuit shown in <FIG> lies in that: the voltage regulating circuit in this embodiment further includes a feedback control unit <NUM>, where the feedback control unit <NUM> herein is mainly configured to receive an output signal Vout of the voltage regulating circuit, and regulate, according to the output signal of the voltage regulating circuit, a second voltage signal output by a voltage boosting unit.

The feedback control unit <NUM> in this embodiment mainly includes: a second sampler <NUM>, a subtracter <NUM>, a proportion integrator <NUM>, a second voltage comparator <NUM>, and a pulse distributor <NUM>, where.

In other words, the second sampler <NUM> herein performs, by using a photocoupler, isolation sampling on an output signal that is between output ends a and d, a subtraction operation is performed, in the subtracter <NUM>, on a sampled voltage value Vf and a second reference voltage Vref, and then a voltage Vcom is obtained after the proportion integrator <NUM> performs integration regulation on the output signal of the subtracter <NUM>.

The second voltage comparator <NUM> generate a Pulse Width Modulation, PWM, signal after receiving Vcom and V_tri <NUM> from a triangle wave generator, and after the PWM signal passes through the pulse distributor <NUM>, drive signals V-gate for driving the voltage boosting unit are output. For example, drive signals V-gate <NUM> and V-gate <NUM> output by the pulse distributor <NUM> herein are used to drive a field-effect transistor of the half-bridge converter (as shown in <FIG>); or drive signals V-gate <NUM>, V-gate <NUM>, V-gate <NUM>, and V-gate <NUM> output by the pulse distributor <NUM> are used to drive a field-effect transistor of a full-bridge converter (as shown in <FIG>).

It may be understood that when an output voltage between the output ends a and d of the voltage regulating circuit increases, the drive signals V-gate <NUM> and V-gate <NUM> decrease, to ensure that a voltage of the whole voltage regulating circuit is stable and reliable.

In other words, the subtracter <NUM> receives the given second reference voltage Vref and a voltage value of the output signal of the voltage regulating circuit, where the output signal is sampled by the second sampler <NUM>; and then the subtracter <NUM> performs a subtraction operation on the given second reference voltage and the voltage value output by the voltage regulating circuit, and inputs a result of the subtraction operation performed by the subtracter <NUM> into the proportion integrator <NUM>, where an output end of the proportion integrator <NUM> is connected to a first input end of the second voltage comparator <NUM>.

The first input end of the second voltage comparator <NUM> receives an output signal of the proportion integrator <NUM>; a second input end of the second voltage comparator <NUM> is connected to a triangle wave generator <NUM>, and receives a triangle wave output by the triangle wave generator <NUM>; and the second voltage comparator <NUM> compares the output signal of the proportion integrator <NUM> with the triangle wave, and inputs the compared output signal into the pulse distributor <NUM>, so that the pulse distributor outputs the drive signal.

It can be known from the foregoing embodiment that, when a first voltage signal Us' output by a main loop unit is less than or equal to a preset first reference voltage, the voltage regulating circuit in this embodiment can output a second voltage signal ΔU by using a voltage boosting unit, and a signal output by the voltage regulating circuit is a sum of the first voltage signal and the second voltage signal. In this embodiment, the conversion efficiency of the voltage regulating circuit is high and power consumption of the voltage regulating circuit is low, and less heat is generated by the voltage regulating circuit, so that the volume of a system in which the voltage regulating circuit is included can be reduced.

<FIG> and <FIG> both are schematic diagrams of a topology of a voltage regulating circuit according to another embodiment of the present invention. A voltage boosting unit shown in <FIG> is a full-bridge converter <NUM>; and as shown in a dotted box in <FIG>, a transformer in the full-bridge converter shown in <FIG> primarily uses a full-bridge circuit, secondly uses a full-wave rectifier, and preferably, uses a full-wave diode rectifier, so that the full-bridge converter shown in <FIG> can improve the conversion efficiency of the voltage boosting unit. A voltage boosting unit shown in <FIG> is a push-pull converter <NUM>; and as shown in a dotted box in <FIG>, a transformer in the push-pull converter shown in <FIG> primarily uses a push-pull circuit, secondly uses a full-wave rectifier, and preferably, uses a full-wave diode rectifier, so that the push-pull converter <NUM> shown in <FIG> can also improve the conversion efficiency of the voltage boosting unit.

In addition, the voltage regulating circuit shown in <FIG> and <FIG> includes a switching control unit and a feedback control unit, where the switching control unit herein is basically the same as the switching control unit shown in <FIG>, and the feedback control unit is basically the same as the switching control unit shown in <FIG>, which are not described in further detail in this embodiment.

Preferably, an output end of the voltage regulating circuit shown in <FIG>, <FIG>, <FIG>, and <FIG> may further be disposed with an inductor (not shown in the figure) configured to perform filtering on an output signal of the voltage regulating circuit, so that the voltage regulating circuit can output a better signal.

Generally, the first reference voltage is <NUM>. 5V; and when a first voltage signal Us' is greater than or equal to <NUM>. 5V, a second voltage signal that can be output by the voltage boosting unit is zero, and in this case, a voltage value output by the voltage regulating circuit is Us.

When Us' is less than <NUM>. 5V, the voltage boosting unit outputs a second voltage signal that is not zero, and a voltage value of the second voltage signal is consistent with a difference obtained by subtracting Us from <NUM>.

Compared with that in the prior art, the efficiency of the voltage regulating circuit in this embodiment is greatly improved, and power consumption of the voltage regulating circuit can be reduced. Correspondingly, in this embodiment, the volume of a system in which the voltage regulating circuit is used can also be reduced.

Claim 1:
A voltage regulating circuit (<NUM>), comprising:
a main loop unit (<NUM>), configured to output, according to an input signal of a voltage source (<NUM>, <NUM>), a first voltage signal whose voltage value is equal to a voltage value of the voltage source (<NUM>, <NUM>);
a voltage boosting unit (<NUM>, <NUM>), configured to output a second voltage signal according to the input signal, wherein a sum of the second voltage signal and the first voltage signal forms an output signal of the voltage regulating circuit (<NUM>);
a switching control unit (<NUM>, <NUM>), configured to compare the first voltage signal with a preset first reference voltage, and when the first voltage signal is greater than or equal to the first reference voltage, control the second voltage signal output by the voltage boosting unit (<NUM>, <NUM>) to be zero; and
a short-circuit switch (<NUM>, <NUM>) connected to the switching control unit (<NUM>, <NUM>), so that the switching control (<NUM>, <NUM>) unit controls, when it is determined that the first voltage signal is greater than or equal to the first reference voltage, the short-circuit switch (<NUM>, <NUM>) to be closed, to enable the second voltage signal output by the voltage boosting unit (<NUM>, <NUM>) to be zero;
characterized in that
the short-circuit switch (<NUM>, <NUM>) is disposed between output ends of the voltage boosting unit (<NUM>, <NUM>) wherein, when the short-circuit switch (<NUM>, <NUM>) is controlled to be closed by the switching control unit (<NUM>), the output ends of the voltage boosting unit (<NUM>) are short-circuited.