JP3567612B2 - Power control device - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a power control device that controls the power supplied to a load by intermittently switching an AC output of an AC power supply by a switching operation of a semiconductor element.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a power control device that controls power supplied to a load by intermittently switching an AC output of an AC power supply by switching operation of a semiconductor element has been used to perform dimming by, for example, adjusting power supplied to a lighting load. Widely used for equipment and the like.
Figure 12 shows a conventional example of light control device A 'using the power control unit, 3-phase 4-wire wiring W ₁ to _W-4 and a plurality of lighting loads L ₁ ~ from the receiving end U having a transformer it is inserted between the L _4, and performs R, S, power control to the lighting load in conjunction with each phase or each phase of T L ₁ ~L ₄ a (light control).
[0003]
The dimmer A 'includes a breaker (not shown) for protecting a circuit when a load terminal is short-circuited, a choke coil (not shown) for a filter, and a bidirectional thyristor (triac) as a semiconductor element for performing a switching operation. ) comprising a Q ₁ to Q _4, the operation unit 2 the gate control circuit based on the input signal from 50 ₁ to 50 ₄ causes a switching operation by applying a control signal to the gate of the triac Q ₁ to Q _4, per unit time controlling the electric power supplied from the receiving end U to the lighting load L ₁ ~L ₄ by controlling the conduction time of the triac Q ₁ to Q _4, it is of the so-called phase control method. Here, since semiconductor elements such as thyristors and triacs have a high withstand capability, circuit elements can be protected by breaking the circuit with a breaker or the like in the event of a short circuit at the load end, and semiconductor elements such as thyristors and triacs can be used. Since ON / OFF switching control can be performed only every half cycle of the AC output from the power receiving end U, the filter is used for the purpose of preventing generation of electric noise or reducing the load on circuit elements at the time of ON / OFF. A choke coil is required.
[0004]
The synchronization circuit 2 ₁ to 2 ₃ for outputting a synchronous signal synchronized with the zero crossing of the phase voltage is provided to the light control device A '. The synchronous circuit 2 ₁ ... and the rectifier circuit 4 for full-wave rectified phase voltages taken from each phase of the wire W ₁ to _W-3, a reference voltage source 5 for generating a predetermined reference voltage, pulsating rectified voltage the a comparator 6 which outputs a synchronizing signal synchronized with the zero crossing of the phase voltage as compared with the reference voltage, the synchronization signal output is respectively supplied to the gate control circuit 50 ₁ to 50 _4.
[0005]
Here, the operation of the light control device A ′ will be described with reference to the waveform diagram of FIG. 13. The pulsating voltage V ₁ obtained by full-wave rectifying the phase voltage Vi is compared with the reference voltage Vr in the comparator 6. The pulse-shaped synchronization signal Vt is output from the comparator 6 during a period in which the pulsating voltage V ₁ near the zero cross of the voltage Vi is lower than the reference voltage Vr. In the gate control circuit 50 ₁ ... at the timing based on the synchronization signal Vt input from the synchronizing circuit 2 ₁ ..., the gate so as to conduct only triac Q ₁ ... a predetermined period corresponding to an input signal from the operation unit 3 Outputs control signal. As a result, the output voltage V ₀ from the dimmer A ′ to the lighting loads L ₁ ... Has a phase-controlled waveform. The period T ₀ during which the triacs Q ₁ are conducting is determined by the magnitude of the input signal from the operation unit 3.
[0006]
[Problems to be solved by the invention]
Incidentally, in the above-described conventional example, the criteria for variations in the power supply frequency and supply voltage, is output ripple voltage V ₁ output from the rectifying circuit 4 from the reference voltage source 5 in accordance with the level of the smoothed DC voltage The voltage Vr is adjusted so that when the power supply voltage (phase voltage Vi) is low, the conduction period of the triacs Q ₁ is longer, and when the power supply voltage (phase voltage Vi) is high, the conduction period is shorter, so that the power is supplied to the lighting loads L ₁ . and corrects the output voltage V ₀ so as to cancel the influence of fluctuations in the power source voltage to the output voltage V ₀ that. However, such correction is possible only when the power supply voltage waveform taken in from the wires W ₁ is a normal sine wave.
[0007]
That is, when the wiring length of the wiring W ₁ from the transformer at the power receiving end U to the dimmer A ′ is long, or when the capacity of the transformer is not sufficient with respect to the load capacity, the 2nd of the power receiving end U is used. even following side phase voltages normal sine wave, when taken into the dimmer a 'may be distorted becomes asymmetrical occurs in the waveform of the phase voltage Vi as shown in FIG. 14. In such a case, the pulsating voltage V ₁ output from the rectifier circuit 4 is also distorted, so that the synchronous circuit 2 ₁ ... Cannot correctly detect the zero cross of the phase voltage Vi. , The synchronization signal Vt 'out of phase is output, and the switching timing of the triacs Q ₁ ... Shifts, or the pulse width of the synchronization signal Vt ′ shifts, so that a predetermined output cannot be obtained, and the illumination loads L ₁ . In such a case, there is a problem that phenomena such as flickering and disappearing occur.
[0008]
SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a power conversion device that prevents a change in power supplied to a load due to a change in a power supply voltage or a power supply frequency.
[0009]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a semiconductor device which is inserted into a power supply path from an AC power supply to a load and performs a switching operation for interrupting the power supply path, and a conduction period of the semiconductor element according to an input signal. A control means for outputting a control signal for determining the power supply voltage, wherein a synchronous signal generating means for generating a synchronous signal synchronized with a zero cross of an AC power supply voltage taken from near the AC power supply in the power supply path, An effective value calculating unit for obtaining an effective value of the AC power supply voltage during a conduction period of the element; and a control signal for obtaining a predetermined load supply power from the input signal and the effective value of the AC power supply voltage based on a function given in advance. a power control device comprising a function unit to the control means for determining, a breaker to protect blocking the circuit when the load end short, at least the semiconductor element and the control hand Also, an impeller-shaped radiator to which circuit components constituting the synchronization signal generating means are attached, and a cooling fan having a rotation axis substantially coincident with the axis of the radiator, and a predetermined gap is provided between the breaker and the radiator. The cooling fan is arranged and provided , and by taking in the AC power supply voltage from the vicinity of the AC power supply, it is possible to suppress the influence of the waveform distortion of the AC power supply voltage due to the wiring length from the AC power supply, Further, by obtaining a control signal that can obtain load supply power according to the input signal by a function given in advance based on the effective value of the AC power supply voltage thus taken in, the AC power supply voltage may vary. However, power that is always determined by the function of the function part, that is, ideal power according to the input signal, can be supplied to the load. The variation of the power supplied to be prevented. Further, the overcurrent detecting bimetal included in the breaker operates by radiating heat from the circuit components, and it is possible to prevent the occurrence of an erroneous operation in which the circuit is erroneously shut off.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
(Embodiment 1)
FIG. 1 is a schematic circuit diagram showing a first embodiment of the present invention. The present embodiment also relates to a dimming device for dimming an illumination load, and the basic configuration is common to the conventional example.
[0011]
Dimming device A of the present embodiment, the receiving end the illumination load from U L ₁ ~L feedline to ₄ (wire W ₁ to _W-3) to be inserted semiconductor element serving triac Q ₁ to Q _4, each a gate control circuit 1 ₁ to 1 ₄ that outputs a control signal to the gate of the triac Q ₁ to Q _4, the gate control circuit 1 ₁ to 1 ₄ synchronous circuit for outputting a synchronous signal synchronized with the zero crossing of the AC power source voltage to 2 and 21 _{to 3,} and an operation section 3 which provides an input signal to instruct the dimming amount of the lighting load L ₁ ~L ₄ to the gate control circuit 1 ₁ to 1 _4, the input signal from the operation unit 3 based on the power receiving by the gate control circuit 1 ₁ to 1 ₄ gives a control signal to the gate of the triac Q ₁ to Q ₄ is a switching operation, controls the conduction time of the triac Q ₁ to Q ₄ per unit time by controlling the power supplied to the lighting load L ₁ ~L ₄ from the end U Performing optical, a power control apparatus of a so-called phase control method. The operation unit 3 can be as remote control device to provide input signals to the gate control circuit 1 ₁ ... wired or wireless.
[0012]
Synchronous circuit 2 ₁ ... is the phase voltage taken from each phase of the wire W ₁ to _W-3 in the vicinity of the receiving end U and rectifying circuit 4 for full-wave rectification, the reference voltage source 5 for generating a predetermined reference voltage, A comparator 6 for comparing the rectified pulsating voltage with the reference voltage and outputting a synchronization signal synchronized with the zero cross of the phase voltage. Here, in the present embodiment, since have taken up the phase voltage from the vicinity of the receiving end U, before being affected by wiring W ₁ always wiring even when the wiring length to _W-4 is longer W ₁ to _W-4 An AC power supply voltage with little waveform distortion can be taken in. Therefore, as compared with the conventional example had incorporated the AC power supply voltage after the effect by the wiring W ₁ to _W-4, it has the advantage that the synchronization signal to eliminate that a phase shift occurs.
[0013]
The gate control circuit 1 ₁ ... Integrates the pulsating voltage output from the rectifier circuit 4 of the synchronization circuit 2 ₁ ... By using the operational amplifier OP ₁ to obtain an effective value of the AC power supply voltage. , A switch SW configured by a transistor or the like to turn on / off the input of the pulsating voltage to the integrator 7, and in response to an input signal from the operation unit 3 at a timing corresponding to a synchronization signal from the synchronization circuit 2 ₁ . A pulse signal generating circuit 8 for outputting a pulse signal having a pulse width of the given width to turn on / off the switch SW, and supplying a predetermined load from the effective value of the AC power supply voltage obtained by the integrator 7 and the input signal from the operation unit 3. And a function section 9 for obtaining a control signal for obtaining power and outputting the control signal to the gates of the triacs Q ₁ . Since the pulsating voltage is input to the integrator 7 via the switch SW only in the period corresponding to the triac Q ₁ ... conduction period, the effective value output from the integrator 7 triac Q ₁ ... of It is the effective value of the AC power supply voltage during the conduction period.
[0014]
On the other hand, the function unit 9 includes two operational amplifiers OP ₂ and OP ₃ , and determines the relationship between the input signal and the effective value of the AC power supply voltage when the AC power supply voltage Vi is a normal sine wave as shown in FIG. A function to be determined is set in advance, and the effective value of the AC power supply voltage corresponding to the input signal obtained from this function is compared with the effective value of the actual AC power supply voltage input from the integrator 7, and from the result, The conduction angle of the triacs Q ₁ ... Is controlled by creating a control signal such that the effective value when the AC power supply voltage is a normal sine wave substantially coincides with the actual effective value. That is, as shown in FIG. 3A, even when a waveform distortion occurs in the AC power supply voltage Vi, the effective value of the actual AC power supply voltage substantially coincides with the normal effective value obtained by the above function. In this manner, the pulse width of the control signal is corrected in the gate control circuits 1 ₁ ..., And the voltage V ₀ according to the input signal from the operation unit 3 is constantly and stably supplied to the illumination loads L ₁ . (C)). Therefore, it is possible to prevent malfunction of the gate control circuits 1 ₁ ... Against asymmetric power supply distortion caused by construction and power supply specifications, and to stabilize the output.
[0015]
By the way, as shown in FIGS. 4 (a) and 4 (b), the dimmer A of this embodiment has circuit components such as triacs Q ₁ ... For one circuit mounted on a flat mounting plate 10 and a cabinet CB. Many are accommodated and arranged inside, and are of a large-capacity type mainly for dimming a large number of illumination loads L ₁ . A circuit breaker B for protection and a choke coil CH for filter which are not shown in the schematic circuit diagram of FIG. As described in the conventional example, the choke coil CH prevents the generation of electrical noise due to the fact that the triacs Q ₁ can be turned on and off only every half cycle of the AC power supply voltage, or prevents the triacs Q ₁ . It is provided for the purpose of reducing the burden. The choke coil CH is formed by winding a winding made of a conductor having a circular or rectangular cross section around a toroidal or cylindrical core, and the phase control is performed by a triac Q ₁ . Flows through the winding, the winding itself vibrates due to the electromagnetic force and generates a growling sound.
[0016]
Therefore, as shown in FIG. 5 (b), when the conductive material is rolled into a strip by a rolling mill to form a winding, one or both sides of the rollers of the rolling mill extend along the longitudinal direction of the winding. If a groove is provided and irregularities are formed on one side (or both sides) of the winding 11 to partially increase the thickness of the winding 11 in the longitudinal direction, the strength of the winding 11 is increased and The generation of a growling sound due to the vibration of the winding as described above can be suppressed. The winding 11 formed in this manner is wound around a bobbin 12 attached to a rectangular frame-shaped core 13 to form a choke coil CH.
[0017]
Further, as another structure for suppressing the vibration of the winding, as shown in FIG. 6, a winding 14 formed in a slightly wide band shape is wound around a cylindrical core 16 to form a choke coil CH. At this time, the insulating material 15 having insulation properties such as urethane may be simultaneously wound, and the insulating material 15 may be interposed between the layers of the winding 14. In this case, the inductance is increased by increasing the number of turns of the winding 14, and electrodes 17 are connected to both ends of the winding 14 at the beginning and end of the winding. Thus, by interposing the vibration isolator 15 between the windings 14, the vibration of the winding 14 can be suppressed by the vibration isolator 15.
[0018]
Alternatively, as another vibration suppressing structure, a number of protrusions 18a are provided on the outer peripheral surface of the bobbin 18 attached to the core 19, and the winding 20 is wound on the protrusions 18a to form the choke coil CH. There are also things. That is, by supporting the winding 20 at multiple points with a large number of projections 18a protruding from the outer peripheral surface of the bobbin 18, the vibration of the winding 20 can be suppressed and the generation of a growling sound can be prevented.
[0019]
In general, the amount of heat generated from circuit components in a power control device greatly changes depending on the use condition of a load (output current from the power control device). However, conventionally, as shown in FIG. The board is used as a plate to promote heat dissipation, and the circuit components are cooled by circulating air in the cabinet CB using a cooling fan or the like disposed above the cabinet CB.
[0020]
On the other hand, as shown in FIG. 8, a plurality of printed circuit boards PB on which circuit components such as a triac Q ₁ ... For one circuit, a breaker B or a choke coil CH are mounted are stacked with a predetermined gap therebetween. Are mounted on the mounting plates 21 ₁ , 21 ₂ , and the mounting plates 21 _1, ... Are mounted in a case 22 in which fans 23 ₁ , 23 ₂ for intake and exhaust are mounted on upper and lower ends 22 a, 22 b in the vertical direction. if, by blowing upward inside the case 22 by driving the fan 23 _1, 23 _2, and air between the gaps provided between the plurality of mounting plates 21 _1, 21 _2, radiator The heat radiated from the mounting plates 21 ₁ also serving as a plate is efficiently discharged to the upper portion of the cabinet CB, and as a result, the heat radiation of a large number of circuit components can be efficiently performed collectively.
[0021]
In addition, a so-called high-speed cutoff product that operates at high speed to reliably protect the circuit element is used for the breaker B, but a bimetal provided inside for detecting an overcurrent is radiated from the circuit component. A malfunction may occur due to heat and may cause unnecessary breakage of the breaker B. However, as shown in FIG. 9, by connecting metal flat heat radiating plates 24a. A choke coil CH, a triac Q _1, and circuit components constituting each circuit are mounted on each radiator plate 24a of the radiator 24, and the cooling fan 25 has its rotation axis substantially aligned with the axis of the radiator 24a. As shown in FIG. 10, a predetermined gap 26 is provided between the breaker B and the radiator 24, and And the circuit components and the breaker B emit is isolated by the air gap 26 prevents a malfunction of the circuit breaker B, as described above. Each of the heat radiating plates 24a is provided with a large number of fins 24b protruding in order to enhance the heat radiating effect.
[0022]
By the way, each of the above fans is often turned on and off in conjunction with turning on the power or detecting the temperature of the installation location. However, since the amount of heat generated from circuit components greatly changes depending on the usage of the load, Depending on the operation rate, the fan is driven even when cooling is not required, causing problems such as unnecessary power consumption and noise.
[0023]
Thus, the fan motor M for rotating the cooling fan 25 is driven by a circuit as shown in FIG. 11, and unnecessary power consumption and generation of noise can be prevented. This circuit is configured to connect the parallel circuit of the photo being connected in parallel to both ends Toraji Star Tr _1, Tr ₂ and the diode D ₁ of the fan motor M and the backflow preventing that a DC motor in series of the DC power source E, a predetermined , And a series circuit of temperature detecting elements TH ₁ , TH ₂ and light emitting diodes LD ₁ , LD ₂ , which are turned on when the temperature exceeds, is connected to both ends of a DC power supply E in parallel with each other. A photocoupler is formed by the photo transistor Tr ₁ and the light emitting diode LD _1, and the photo transistor Tr ₂ and the light emitting diode LD ₂ . Further, the temperature detecting elements TH ₁ and TH ₂ are those whose contacts are closed when the resistance value of the thermistor that changes depending on the ambient temperature, for example, reaches a predetermined threshold value. Is set. That is, in this circuit configuration, the temperature detection elements TH ₁ and TH ₂ are sequentially turned on in accordance with the ambient temperature, and the power supplied to the fan motor M can be changed in a stepwise manner. In this way, it is possible to perform cooling in accordance with the condition, and to prevent problems such as unnecessary power consumption and noise. Alternatively, a DC output corresponding to a change in the resistance value of the thermistor may be amplified by an amplifier and used as a power supply for driving a fan motor. In this case, the minimum voltage that can rotate the fan stably should be applied even when the ambient temperature has not risen so much and the output voltage from the amplifier has almost no output. Just fine .
[0024]
【The invention's effect】
According to the first aspect of the present invention, a semiconductor element which is inserted into a power supply path from an AC power supply to a load and performs a switching operation for intermittently connecting the power supply path, and outputs a control signal for determining a conduction period of the semiconductor element according to an input signal. A power control device comprising: a control signal generating means for generating a synchronizing signal synchronized with a zero-cross of an AC power supply voltage taken from the vicinity of the AC power supply in a power supply path; An effective value calculating unit for obtaining an effective value of the control unit, and a function unit for obtaining a control signal for obtaining a predetermined load supply power from the input signal and the effective value of the AC power supply voltage based on a function given in advance. a power control device including a breaker that protects blocking the circuit when the load end short, the at least semiconductor element control means and synchronizing signal generating means It has an impeller-shaped radiator to which the circuit components to be mounted are attached, and a cooling fan whose rotation axis is substantially aligned with the axis of the radiator, and provides a predetermined gap between the breaker and the radiator to cool the cooling fan. since composed by disposing an AC power supply voltage can be suppressed the influence of the waveform distortion of the AC power supply voltage due to wiring from the AC power source by taking from the AC power source near the, also incorporated in this way By obtaining a control signal such that the load supply power according to the input signal is obtained by a function given in advance based on the effective value of the AC power supply voltage, the function of the function section is always used even if the AC power supply voltage fluctuates. determined power, i.e. it can supply the ideal power corresponding to the input signal to the load, as a result, it is possible to prevent variations in the supply power to the load due to variations in power supply voltage or the power frequency, Et to operate in the heat dissipation from the bimetal circuit components for overcurrent detection breaker comprising, there is an effect that occurrence of a malfunction such as blocked accidentally circuit can be prevented.
[Brief description of the drawings]
FIG. 1 is a schematic circuit diagram showing a first embodiment.
FIG. 2 is a waveform chart for explaining the above operation.
FIG. 3 is a waveform chart for explaining the operation of the above.
FIG. 4A is a view for explaining an installation state of the above, and FIG. 4B is a perspective view showing a structure of the same.
FIGS. 5A and 5B show the structure of the choke coil in the above embodiment, wherein FIG. 5A is a plan view and FIG. 5B is a perspective view of a winding.
FIG. 6 is a perspective view showing another structure of the choke coil of the above.
FIG. 7 is a plan view showing still another structure of the choke coil in the above.
FIG. 8 is a sectional view showing another structure of the above.
FIG. 9 is a perspective view showing still another structure of the above.
FIG. 10 is a partially broken side view showing the structure of the above.
FIG. 11 is a circuit diagram showing a drive circuit for a cooling fan in the above power supply system.
FIG. 12 is a schematic circuit diagram showing a conventional example.
FIG. 13 is a waveform chart for explaining the above operation.
FIG. 14 is a waveform chart for explaining the above operation.
[Explanation of symbols]
A dimmer L ₁ … lighting load 1 ₁ … gate control circuit 2 ₁ … synchronization circuit 3 operation section 7 integrator 8 pulse signal generator 9 function section SW switch

Claims (1)

A power supply comprising: a semiconductor element that is inserted into a power supply path from an AC power supply to a load and performs a switching operation for interrupting the power supply path; and control means that outputs a control signal that determines a conduction period of the semiconductor element according to an input signal. The control device includes a synchronizing signal generating means for generating a synchronizing signal synchronized with a zero cross of the AC power supply voltage taken from the vicinity of the AC power supply in the power supply path, and an effective value for obtaining an effective value of the AC power supply voltage during a conduction period of the semiconductor element. A power control apparatus comprising: a calculation unit; and a function unit that obtains a control signal that can obtain a predetermined load supply power from an input signal and an effective value of an AC power supply voltage based on a function given in advance. A circuit breaker for interrupting and protecting a circuit when a load terminal is short-circuited, and a circuit component constituting at least a semiconductor element, a control means, and a synchronization signal generation means. It has an impeller-shaped radiator attached, and a cooling fan whose rotation axis is approximately aligned with the axis of the radiator, and provides a predetermined gap between the breaker and the radiator to arrange the cooling fan. the power control apparatus characterized by comprising.

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